feat: add user color customization and metadata handling

- Implemented `useUserColor` hook to manage user profile color stored in avatar PNG metadata.
- Added `useOtherUserColor` hook to fetch and cache colors from other users' avatars.
- Created utility functions for reading and writing PNG metadata, enabling color embedding and extraction.
- Refactored `SearchResultGroup`, `RoomInput`, `Message`, `RoomPinMenu`, and `Notifications` components to utilize user color for display.
- Introduced `UserColorPicker` component in settings for users to select and save their profile color.
- Enhanced notification and message rendering to prioritize custom user colors over legacy colors.

src/app/components/message/Reply.tsx

@@ -2,7 +2,7 @@ import { Box, Icon, Icons, Text, as, color, toRem } from 'folds';
 import { EventTimelineSet, Room } from 'matrix-js-sdk';
 import React, { MouseEventHandler, ReactNode, useCallback, useMemo } from 'react';
 import classNames from 'classnames';
-import { getMemberDisplayName, trimReplyFromBody } from '../../utils/room';
+import { getMemberAvatarMxc, getMemberDisplayName, trimReplyFromBody } from '../../utils/room';
 import { getMxIdLocalPart } from '../../utils/matrix';
 import { LinePlaceholder } from './placeholder';
 import { randomNumberBetween } from '../../utils/common';
@@ -12,6 +12,7 @@ import { scaleSystemEmoji } from '../../plugins/react-custom-html-parser';
 import { useRoomEvent } from '../../hooks/useRoomEvent';
 import colorMXID from '../../../util/colorMXID';
 import { GetMemberPowerTag } from '../../hooks/useMemberPowerTag';
+import { useOtherUserColor } from '../../hooks/useUserColor';
 
 type ReplyLayoutProps = {
   userColor?: string;
@@ -86,10 +87,13 @@ export const Reply = as<'div', ReplyProps>(
 
     const { body } = replyEvent?.getContent() ?? {};
     const sender = replyEvent?.getSender();
+    const senderAvatarMxc = sender ? getMemberAvatarMxc(room, sender) : undefined;
+    const customUserColor = useOtherUserColor(sender ?? '', senderAvatarMxc);
     const powerTag = sender ? getMemberPowerTag?.(sender) : undefined;
     const tagColor = powerTag?.color ? accessibleTagColors?.get(powerTag.color) : undefined;
 
-    const usernameColor = legacyUsernameColor ? colorMXID(sender ?? replyEventId) : tagColor;
+    // Priority: custom user color > tag color (non-legacy) > colorMXID (legacy)
+    const usernameColor = customUserColor ?? (legacyUsernameColor ? colorMXID(sender ?? replyEventId) : tagColor);
 
     const fallbackBody = replyEvent?.isRedacted() ? (
       <MessageDeletedContent />

src/app/features/call/CallOverlay.tsx

@@ -605,7 +605,20 @@ export function CallOverlay() {
           <Text size="T300" truncate>
             {isConnecting ? 'Connecting...' : `In Call - ${room?.name ?? 'Unknown Room'}`}
             {selectedRoomId === activeCall.roomId && (
-              <span style={{ opacity: 0.7, fontSize: '0.85em' }}> (Current Room)</span>
+              <TooltipProvider
+                position="Top"
+                offset={4}
+                tooltip={<Tooltip><Text>Current Room</Text></Tooltip>}
+              >
+                {(triggerRef) => (
+                  <Icon 
+                    ref={triggerRef}
+                    size="100" 
+                    src={Icons.Check} 
+                    style={{ marginLeft: '4px', opacity: 0.7, verticalAlign: 'middle' }} 
+                  />
+                )}
+              </TooltipProvider>
             )}
           </Text>
           {selectedRoomId !== activeCall.roomId && (

src/app/features/call/CallService.ts

@@ -31,6 +31,16 @@ type CallEventListener = (event: CallEvent) => void;
 /** The Matrix state event type for call membership (MSC3401) */
 const CALL_MEMBER_EVENT_TYPE = 'org.matrix.msc3401.call.member';
 
+/**
+ * Service for managing Matrix RTC calls via LiveKit
+ * Handles LiveKit connections, media streams, call state, and Matrix room signaling
+ */
+/** How often to refresh call membership to prevent expiry (45 minutes) */
+const MEMBERSHIP_REFRESH_INTERVAL_MS = 45 * 60 * 1000;
+
+/** Call membership expiry time (1 hour) */
+const MEMBERSHIP_EXPIRY_MS = 60 * 60 * 1000;
+
 /**
  * Service for managing Matrix RTC calls via LiveKit
  * Handles LiveKit connections, media streams, call state, and Matrix room signaling
@@ -48,6 +58,12 @@ export class CallService {
 
   private livekitJwt: LiveKitJWTResponse | null = null;
 
+  private membershipRefreshInterval: ReturnType<typeof setInterval> | null = null;
+
+  private currentCallId: string | null = null;
+
+  private wasMutedBeforeDeafen = false;
+
   /**
    * Creates a new CallService instance
    * @param config - Service configuration including homeserver and LiveKit URLs
@@ -137,7 +153,7 @@ export class CallService {
               {
                 device_id: this.config.deviceId,
                 session_id: callId,
-                expires_ts: Date.now() + 1000 * 60 * 60, // 1 hour expiry
+                expires_ts: Date.now() + MEMBERSHIP_EXPIRY_MS,
                 feeds: [
                   { purpose: 'usermedia' },
                 ],
@@ -170,6 +186,44 @@ export class CallService {
     }
   }
 
+  /**
+   * Starts periodic refresh of call membership to prevent expiry
+   * Refreshes every 45 minutes to ensure the 1 hour expiry is never reached
+   * @param roomId - The Matrix room ID
+   * @param callId - The unique call ID
+   */
+  private startMembershipRefresh(roomId: string, callId: string): void {
+    this.stopMembershipRefresh();
+
+    this.membershipRefreshInterval = setInterval(async () => {
+      if (!this.activeCall || this.activeCall.roomId !== roomId) {
+        this.stopMembershipRefresh();
+        return;
+      }
+
+      try {
+        console.log('Refreshing call membership to prevent expiry');
+        await this.sendCallMemberEvent(roomId, callId, true);
+        console.log('Call membership refreshed successfully');
+      } catch (error) {
+        console.error('Failed to refresh call membership:', error);
+      }
+    }, MEMBERSHIP_REFRESH_INTERVAL_MS);
+
+    console.log('Started call membership refresh interval (every 45 minutes)');
+  }
+
+  /**
+   * Stops the membership refresh interval
+   */
+  private stopMembershipRefresh(): void {
+    if (this.membershipRefreshInterval) {
+      clearInterval(this.membershipRefreshInterval);
+      this.membershipRefreshInterval = null;
+      console.log('Stopped call membership refresh interval');
+    }
+  }
+
   /**
    * Starts a call in the specified room
    * @param roomId - The Matrix room ID to start the call in
@@ -271,6 +325,10 @@ export class CallService {
       // Step 5: Send Matrix state event to announce participation
       // This state event will be rendered in the timeline as a "joined the call" notification
       await this.sendCallMemberEvent(roomId, callId, true);
+      this.currentCallId = callId;
+
+      // Step 6: Start periodic membership refresh to prevent expiry after 1 hour
+      this.startMembershipRefresh(roomId, callId);
 
       console.log('Announced call participation to Matrix room');
 
@@ -651,6 +709,9 @@ export class CallService {
     const { roomId } = this.activeCall;
     this.setState(CallState.Disconnecting);
 
+    // Stop the membership refresh interval
+    this.stopMembershipRefresh();
+
     // Stop any dialing loop and play departure sound
     getCallSounds().stopDialingLoop();
     getCallSounds().playSound(CallSoundType.CallDepart);
@@ -674,6 +735,7 @@ export class CallService {
 
     this.activeCall = null;
     this.livekitJwt = null;
+    this.currentCallId = null;
 
     this.emit({
       type: CallEventType.StateChanged,
@@ -712,6 +774,9 @@ export class CallService {
       this.livekitRoom.localParticipant.setMetadata(metadata).catch((err) => {
         console.warn('Failed to set participant metadata:', err);
       });
+
+      // Play undeafen sound
+      getCallSounds().playSound(CallSoundType.Undeafen);
     }
     
     this.livekitRoom.localParticipant.setMicrophoneEnabled(!newMuteState);
@@ -749,16 +814,23 @@ export class CallService {
       });
     });
 
-    // Also mute/unmute our mic when deafening (silently - no mute sound)
+    // Handle mic muting when deafening
-    // Only change mic state if it doesn't match deafen state
+    if (newDeafenState) {
-    if (newDeafenState && !this.activeCall.isMuted) {
+      // Remember if user was muted before deafening
-      // Deafening - also mute mic
+      this.wasMutedBeforeDeafen = this.activeCall.isMuted;
-      this.livekitRoom.localParticipant.setMicrophoneEnabled(false);
+      
-      this.activeCall.isMuted = true;
+      // Deafening - always mute mic
-    } else if (!newDeafenState && this.activeCall.isMuted) {
+      if (!this.activeCall.isMuted) {
-      // Undeafening - also unmute mic
+        this.livekitRoom.localParticipant.setMicrophoneEnabled(false);
-      this.livekitRoom.localParticipant.setMicrophoneEnabled(true);
+        this.activeCall.isMuted = true;
-      this.activeCall.isMuted = false;
+      }
+    } else {
+      // Undeafening - only unmute if user wasn't muted before deafening
+      if (!this.wasMutedBeforeDeafen && this.activeCall.isMuted) {
+        this.livekitRoom.localParticipant.setMicrophoneEnabled(true);
+        this.activeCall.isMuted = false;
+      }
+      this.wasMutedBeforeDeafen = false;
     }
 
     // Broadcast deafen state to other participants via metadata
@@ -943,6 +1015,7 @@ export class CallService {
    * Cleans up resources
    */
   dispose(): void {
+    this.stopMembershipRefresh();
     this.endCall();
     this.listeners.clear();
   }

src/app/features/message-search/SearchResultGroup.tsx

@@ -51,6 +51,147 @@ import {
 } from '../../hooks/useMemberPowerTag';
 import { useRoomCreators } from '../../hooks/useRoomCreators';
 import { useRoomCreatorsTag } from '../../hooks/useRoomCreatorsTag';
+import { useOtherUserColor } from '../../hooks/useUserColor';
+
+/**
+ * Props for SearchResultItem component
+ */
+type SearchResultItemProps = {
+  room: Room;
+  item: ResultItem;
+  getMemberPowerTag: ReturnType<typeof useGetMemberPowerTag>;
+  accessibleTagColors: Map<string, string> | undefined;
+  renderMatrixEvent: ReturnType<typeof useMatrixEventRenderer<[IEventWithRoomId, string, GetContentCallback]>>;
+  handleOpenClick: MouseEventHandler;
+  legacyUsernameColor?: boolean;
+  hour24Clock: boolean;
+  dateFormatString: string;
+};
+
+/**
+ * Component to render a single search result item with proper hook usage
+ */
+function SearchResultItem({
+  room,
+  item,
+  getMemberPowerTag,
+  accessibleTagColors,
+  renderMatrixEvent,
+  handleOpenClick,
+  legacyUsernameColor,
+  hour24Clock,
+  dateFormatString,
+}: SearchResultItemProps) {
+  const mx = useMatrixClient();
+  const useAuthentication = useMediaAuthentication();
+  const { event } = item;
+
+  const displayName =
+    getMemberDisplayName(room, event.sender) ??
+    getMxIdLocalPart(event.sender) ??
+    event.sender;
+  const senderAvatarMxc = getMemberAvatarMxc(room, event.sender);
+
+  const relation = event.content['m.relates_to'];
+  const mainEventId =
+    relation?.rel_type === RelationType.Replace ? relation.event_id : event.event_id;
+
+  const getContent = (() =>
+    event.content['m.new_content'] ?? event.content) as GetContentCallback;
+
+  const replyEventId = relation?.['m.in_reply_to']?.event_id;
+  const threadRootId =
+    relation?.rel_type === RelationType.Thread ? relation.event_id : undefined;
+
+  // Get custom user color from avatar metadata
+  const customUserColor = useOtherUserColor(event.sender, senderAvatarMxc);
+
+  const memberPowerTag = getMemberPowerTag(event.sender);
+  const tagColor = memberPowerTag?.color
+    ? accessibleTagColors?.get(memberPowerTag.color)
+    : undefined;
+  const tagIconSrc = memberPowerTag?.icon
+    ? getPowerTagIconSrc(mx, useAuthentication, memberPowerTag.icon)
+    : undefined;
+
+  // Priority: custom user color > tag color (non-legacy) > colorMXID (legacy)
+  const usernameColor = customUserColor ?? (legacyUsernameColor ? colorMXID(event.sender) : tagColor);
+
+  return (
+    <SequenceCard
+      key={event.event_id}
+      style={{ padding: config.space.S400 }}
+      variant="SurfaceVariant"
+      direction="Column"
+    >
+      <ModernLayout
+        before={
+          <AvatarBase>
+            <Avatar size="300">
+              <UserAvatar
+                userId={event.sender}
+                src={
+                  senderAvatarMxc
+                    ? mxcUrlToHttp(
+                        mx,
+                        senderAvatarMxc,
+                        useAuthentication,
+                        48,
+                        48,
+                        'crop'
+                      ) ?? undefined
+                    : undefined
+                }
+                alt={displayName}
+                renderFallback={() => <Icon size="200" src={Icons.User} filled />}
+              />
+            </Avatar>
+          </AvatarBase>
+        }
+      >
+        <Box gap="300" justifyContent="SpaceBetween" alignItems="Center" grow="Yes">
+          <Box gap="200" alignItems="Baseline">
+            <Box alignItems="Center" gap="200">
+              <Username style={{ color: usernameColor }}>
+                <Text as="span" truncate>
+                  <UsernameBold>{displayName}</UsernameBold>
+                </Text>
+              </Username>
+              {tagIconSrc && <PowerIcon size="100" iconSrc={tagIconSrc} />}
+            </Box>
+            <Time
+              ts={event.origin_server_ts}
+              hour24Clock={hour24Clock}
+              dateFormatString={dateFormatString}
+            />
+          </Box>
+          <Box shrink="No" gap="200" alignItems="Center">
+            <Chip
+              data-event-id={mainEventId}
+              onClick={handleOpenClick}
+              variant="Secondary"
+              radii="400"
+            >
+              <Text size="T200">Open</Text>
+            </Chip>
+          </Box>
+        </Box>
+        {replyEventId && (
+          <Reply
+            room={room}
+            replyEventId={replyEventId}
+            threadRootId={threadRootId}
+            onClick={handleOpenClick}
+            getMemberPowerTag={getMemberPowerTag}
+            accessibleTagColors={accessibleTagColors}
+            legacyUsernameColor={legacyUsernameColor}
+          />
+        )}
+        {renderMatrixEvent(event.type, false, event, displayName, getContent)}
+      </ModernLayout>
+    </SequenceCard>
+  );
+}
 
 type SearchResultGroupProps = {
   room: Room;
@@ -213,111 +354,20 @@ export function SearchResultGroup({
         </Box>
       </Header>
       <Box direction="Column" gap="100">
-        {items.map((item) => {
+        {items.map((item) => (
-          const { event } = item;
+          <SearchResultItem
-
+            key={item.event.event_id}
-          const displayName =
+            room={room}
-            getMemberDisplayName(room, event.sender) ??
+            item={item}
-            getMxIdLocalPart(event.sender) ??
+            getMemberPowerTag={getMemberPowerTag}
-            event.sender;
+            accessibleTagColors={accessibleTagColors}
-          const senderAvatarMxc = getMemberAvatarMxc(room, event.sender);
+            renderMatrixEvent={renderMatrixEvent}
-
+            handleOpenClick={handleOpenClick}
-          const relation = event.content['m.relates_to'];
+            legacyUsernameColor={legacyUsernameColor}
-          const mainEventId =
+            hour24Clock={hour24Clock}
-            relation?.rel_type === RelationType.Replace ? relation.event_id : event.event_id;
+            dateFormatString={dateFormatString}
-
+          />
-          const getContent = (() =>
+        ))}
-            event.content['m.new_content'] ?? event.content) as GetContentCallback;
-
-          const replyEventId = relation?.['m.in_reply_to']?.event_id;
-          const threadRootId =
-            relation?.rel_type === RelationType.Thread ? relation.event_id : undefined;
-
-          const memberPowerTag = getMemberPowerTag(event.sender);
-          const tagColor = memberPowerTag?.color
-            ? accessibleTagColors?.get(memberPowerTag.color)
-            : undefined;
-          const tagIconSrc = memberPowerTag?.icon
-            ? getPowerTagIconSrc(mx, useAuthentication, memberPowerTag.icon)
-            : undefined;
-
-          const usernameColor = legacyUsernameColor ? colorMXID(event.sender) : tagColor;
-
-          return (
-            <SequenceCard
-              key={event.event_id}
-              style={{ padding: config.space.S400 }}
-              variant="SurfaceVariant"
-              direction="Column"
-            >
-              <ModernLayout
-                before={
-                  <AvatarBase>
-                    <Avatar size="300">
-                      <UserAvatar
-                        userId={event.sender}
-                        src={
-                          senderAvatarMxc
-                            ? mxcUrlToHttp(
-                                mx,
-                                senderAvatarMxc,
-                                useAuthentication,
-                                48,
-                                48,
-                                'crop'
-                              ) ?? undefined
-                            : undefined
-                        }
-                        alt={displayName}
-                        renderFallback={() => <Icon size="200" src={Icons.User} filled />}
-                      />
-                    </Avatar>
-                  </AvatarBase>
-                }
-              >
-                <Box gap="300" justifyContent="SpaceBetween" alignItems="Center" grow="Yes">
-                  <Box gap="200" alignItems="Baseline">
-                    <Box alignItems="Center" gap="200">
-                      <Username style={{ color: usernameColor }}>
-                        <Text as="span" truncate>
-                          <UsernameBold>{displayName}</UsernameBold>
-                        </Text>
-                      </Username>
-                      {tagIconSrc && <PowerIcon size="100" iconSrc={tagIconSrc} />}
-                    </Box>
-                    <Time
-                      ts={event.origin_server_ts}
-                      hour24Clock={hour24Clock}
-                      dateFormatString={dateFormatString}
-                    />
-                  </Box>
-                  <Box shrink="No" gap="200" alignItems="Center">
-                    <Chip
-                      data-event-id={mainEventId}
-                      onClick={handleOpenClick}
-                      variant="Secondary"
-                      radii="400"
-                    >
-                      <Text size="T200">Open</Text>
-                    </Chip>
-                  </Box>
-                </Box>
-                {replyEventId && (
-                  <Reply
-                    room={room}
-                    replyEventId={replyEventId}
-                    threadRootId={threadRootId}
-                    onClick={handleOpenClick}
-                    getMemberPowerTag={getMemberPowerTag}
-                    accessibleTagColors={accessibleTagColors}
-                    legacyUsernameColor={legacyUsernameColor}
-                  />
-                )}
-                {renderMatrixEvent(event.type, false, event, displayName, getContent)}
-              </ModernLayout>
-            </SequenceCard>
-          );
-        })}
       </Box>
     </Box>
   );

src/app/features/room/RoomInput.tsx

@@ -117,6 +117,8 @@ import { useTheme } from '../../hooks/useTheme';
 import { useRoomCreatorsTag } from '../../hooks/useRoomCreatorsTag';
 import { usePowerLevelTags } from '../../hooks/usePowerLevelTags';
 import { useComposingCheck } from '../../hooks/useComposingCheck';
+import { useOtherUserColor } from '../../hooks/useUserColor';
+import { getMemberAvatarMxc } from '../../utils/room';
 
 interface RoomInputProps {
   editor: Editor;
@@ -142,6 +144,7 @@ export const RoomInput = forwardRef<HTMLDivElement, RoomInputProps>(
     const [msgDraft, setMsgDraft] = useAtom(roomIdToMsgDraftAtomFamily(roomId));
     const [replyDraft, setReplyDraft] = useAtom(roomIdToReplyDraftAtomFamily(roomId));
     const replyUserID = replyDraft?.userId;
+    const replyAvatarMxc = replyUserID ? getMemberAvatarMxc(room, replyUserID) : undefined;
 
     const powerLevelTags = usePowerLevelTags(room, powerLevels);
     const creatorsTag = useRoomCreatorsTag();
@@ -153,12 +156,16 @@ export const RoomInput = forwardRef<HTMLDivElement, RoomInputProps>(
       powerLevelTags
     );
 
+    // Get custom user color from avatar metadata
+    const replyCustomColor = useOtherUserColor(replyUserID ?? '', replyAvatarMxc);
+
     const replyPowerTag = replyUserID ? getMemberPowerTag(replyUserID) : undefined;
     const replyPowerColor = replyPowerTag?.color
       ? accessibleTagColors.get(replyPowerTag.color)
       : undefined;
+    // Priority: custom user color > legacy/direct colorMXID > tag color
     const replyUsernameColor =
-      legacyUsernameColor || direct ? colorMXID(replyUserID ?? '') : replyPowerColor;
+      replyCustomColor ?? (legacyUsernameColor || direct ? colorMXID(replyUserID ?? '') : replyPowerColor);
 
     const [uploadBoard, setUploadBoard] = useState(true);
     const [selectedFiles, setSelectedFiles] = useAtom(roomIdToUploadItemsAtomFamily(roomId));

src/app/features/room/message/Message.tsx

@@ -80,6 +80,7 @@ import { PowerIcon } from '../../../components/power';
 import colorMXID from '../../../../util/colorMXID';
 import { getPowerTagIconSrc } from '../../../hooks/useMemberPowerTag';
 import { Presence, useUserPresence } from '../../../hooks/useUserPresence';
+import { useOtherUserColor } from '../../../hooks/useUserColor';
 
 export type ReactionHandler = (keyOrMxc: string, shortcode: string) => void;
 
@@ -736,6 +737,9 @@ export const Message = as<'div', MessageProps>(
       getMemberDisplayName(room, senderId) ?? getMxIdLocalPart(senderId) ?? senderId;
     const senderAvatarMxc = getMemberAvatarMxc(room, senderId);
 
+    // Get custom user color from avatar metadata (takes priority)
+    const customUserColor = useOtherUserColor(senderId, senderAvatarMxc);
+
     const tagColor = memberPowerTag?.color
       ? accessibleTagColors?.get(memberPowerTag.color)
       : undefined;
@@ -743,7 +747,8 @@ export const Message = as<'div', MessageProps>(
       ? getPowerTagIconSrc(mx, useAuthentication, memberPowerTag.icon)
       : undefined;
 
-    const usernameColor = legacyUsernameColor ? colorMXID(senderId) : tagColor;
+    // Priority: custom user color > tag color (non-legacy) > colorMXID (legacy)
+    const usernameColor = customUserColor ?? (legacyUsernameColor ? colorMXID(senderId) : tagColor);
 
     const headerJSX = !collapse && (
       <Box

src/app/features/room/room-pin-menu/RoomPinMenu.tsx

@@ -86,6 +86,7 @@ import {
   useGetMemberPowerTag,
 } from '../../../hooks/useMemberPowerTag';
 import { useRoomCreatorsTag } from '../../../hooks/useRoomCreatorsTag';
+import { useOtherUserColor } from '../../../hooks/useUserColor';
 
 type PinnedMessageProps = {
   room: Room;
@@ -179,6 +180,9 @@ function PinnedMessage({
   const senderAvatarMxc = getMemberAvatarMxc(room, sender);
   const getContent = (() => pinnedEvent.getContent()) as GetContentCallback;
 
+  // Get custom user color from avatar metadata
+  const customUserColor = useOtherUserColor(sender, senderAvatarMxc);
+
   const memberPowerTag = getMemberPowerTag(sender);
   const tagColor = memberPowerTag?.color
     ? accessibleTagColors?.get(memberPowerTag.color)
@@ -187,7 +191,8 @@ function PinnedMessage({
     ? getPowerTagIconSrc(mx, useAuthentication, memberPowerTag.icon)
     : undefined;
 
-  const usernameColor = legacyUsernameColor ? colorMXID(sender) : tagColor;
+  // Priority: custom user color > tag color (non-legacy) > colorMXID (legacy)
+  const usernameColor = customUserColor ?? (legacyUsernameColor ? colorMXID(sender) : tagColor);
 
   return (
     <ModernLayout

src/app/features/settings/general/General.tsx

@@ -12,6 +12,7 @@ import {
   Box,
   Button,
   Chip,
+  color,
   config,
   Header,
   Icon,
@@ -27,6 +28,7 @@ import {
   Text,
   toRem,
 } from 'folds';
+import { HexColorPicker } from 'react-colorful';
 import { isKeyHotkey } from 'is-hotkey';
 import FocusTrap from 'focus-trap-react';
 import { Page, PageContent, PageHeader } from '../../../components/page';
@@ -50,6 +52,8 @@ import { useMessageLayoutItems } from '../../../hooks/useMessageLayout';
 import { useMessageSpacingItems } from '../../../hooks/useMessageSpacing';
 import { useDateFormatItems } from '../../../hooks/useDateFormat';
 import { SequenceCardStyle } from '../styles.css';
+import { HexColorPickerPopOut } from '../../../components/HexColorPickerPopOut';
+import { useUserColor } from '../../../hooks/useUserColor';
 
 type ThemeSelectorProps = {
   themeNames: Record<string, string>;
@@ -427,10 +431,131 @@ function Appearance() {
       <SequenceCard className={SequenceCardStyle} variant="SurfaceVariant" direction="Column">
         <SettingTile title="Page Zoom" after={<PageZoomInput />} />
       </SequenceCard>
+
+      <UserColorPicker />
     </Box>
   );
 }
 
+/**
+ * Color picker component for user's profile color
+ * Stored in avatar PNG metadata, visible to other Paarrot users
+ */
+function UserColorPicker() {
+  const [userColor, setUserColor, loading] = useUserColor();
+  const [localColor, setLocalColor] = useState(userColor ?? '#3b82f6');
+  const [saving, setSaving] = useState(false);
+  const [error, setError] = useState<string>();
+
+  // Update local color when avatar color changes
+  useEffect(() => {
+    if (userColor) {
+      setLocalColor(userColor);
+    }
+  }, [userColor]);
+
+  const handleColorChange = (newColor: string) => {
+    setLocalColor(newColor);
+    setError(undefined);
+  };
+
+  const handleSaveColor = async () => {
+    setSaving(true);
+    setError(undefined);
+    try {
+      await setUserColor(localColor);
+    } catch (e) {
+      setError('Failed to save. Make sure you have an avatar set.');
+    }
+    setSaving(false);
+  };
+
+  const handleRemoveColor = async () => {
+    setSaving(true);
+    setError(undefined);
+    try {
+      await setUserColor(undefined);
+      setLocalColor('#3b82f6');
+    } catch (e) {
+      setError('Failed to remove color.');
+    }
+    setSaving(false);
+  };
+
+  return (
+    <SequenceCard className={SequenceCardStyle} variant="SurfaceVariant" direction="Column">
+      <SettingTile
+        title="Profile Color"
+        description="Embedded in your avatar. Other Paarrot users will see this color."
+        after={
+          <Box alignItems="Center" gap="200">
+            {loading ? (
+              <Text size="T300" style={{ opacity: 0.7 }}>Loading...</Text>
+            ) : (
+              <HexColorPickerPopOut
+                picker={
+                  <Box direction="Column" gap="200">
+                    <HexColorPicker color={localColor} onChange={handleColorChange} />
+                    <Box gap="100" alignItems="Center">
+                      <Input
+                        size="300"
+                        variant="Secondary"
+                        style={{ width: toRem(100) }}
+                        value={localColor}
+                        onChange={(e) => {
+                          setLocalColor(e.target.value);
+                          setError(undefined);
+                        }}
+                      />
+                      <Button
+                        size="300"
+                        variant="Primary"
+                        fill="Solid"
+                        radii="300"
+                        onClick={handleSaveColor}
+                        disabled={saving}
+                      >
+                        <Text size="B300">{saving ? 'Saving...' : 'Save'}</Text>
+                      </Button>
+                    </Box>
+                    {error && (
+                      <Text size="T200" style={{ color: color.Critical.Main }}>{error}</Text>
+                    )}
+                  </Box>
+                }
+                onRemove={userColor ? handleRemoveColor : undefined}
+              >
+                {(onOpen) => (
+                  <Button
+                    size="300"
+                    variant="Secondary"
+                    fill="Soft"
+                    radii="300"
+                    onClick={onOpen}
+                    disabled={saving}
+                    before={
+                      <Box
+                        style={{
+                          width: toRem(16),
+                          height: toRem(16),
+                          borderRadius: toRem(4),
+                          backgroundColor: userColor ?? localColor,
+                        }}
+                      />
+                    }
+                  >
+                    <Text size="T300">{userColor ? 'Change' : 'Choose'}</Text>
+                  </Button>
+                )}
+              </HexColorPickerPopOut>
+            )}
+          </Box>
+        }
+      />
+    </SequenceCard>
+  );
+}
+
 type DateHintProps = {
   hasChanges: boolean;
   handleReset: () => void;

src/app/hooks/useUserColor.ts

@@ -0,0 +1,201 @@
+import { useCallback, useEffect, useState } from 'react';
+import { MatrixClient } from 'matrix-js-sdk';
+import { useMatrixClient } from './useMatrixClient';
+import { useMediaAuthentication } from './useMediaAuthentication';
+import { mxcUrlToHttp } from '../utils/matrix';
+import { embedColorInPNG, extractColorFromPNG, fetchAndExtractColor, removeColorFromPNG } from '../utils/pngMetadata';
+
+/**
+ * Fetches the user's current avatar as raw PNG data
+ */
+async function fetchAvatarData(
+  mx: MatrixClient,
+  avatarMxc: string,
+  useAuthentication: boolean
+): Promise<ArrayBuffer | null> {
+  const url = mxcUrlToHttp(mx, avatarMxc, useAuthentication);
+  if (!url) return null;
+
+  try {
+    const response = await fetch(url);
+    if (!response.ok) return null;
+    return await response.arrayBuffer();
+  } catch {
+    return null;
+  }
+}
+
+/**
+ * Hook to manage the user's chosen profile color, stored in avatar PNG metadata
+ * The color is embedded in the PNG tEXt chunk and syncs via the avatar
+ * @returns The current color, a setter function, and loading state
+ */
+export function useUserColor(): [
+  string | undefined,
+  (color: string | undefined) => Promise<void>,
+  boolean
+] {
+  const mx = useMatrixClient();
+  const useAuthentication = useMediaAuthentication();
+  const [color, setColor] = useState<string | undefined>();
+  const [loading, setLoading] = useState(true);
+
+  // Extract color from current avatar on mount and when profile changes
+  useEffect(() => {
+    const loadColor = async () => {
+      setLoading(true);
+      try {
+        const userId = mx.getUserId();
+        if (!userId) {
+          setLoading(false);
+          return;
+        }
+
+        const profile = await mx.getProfileInfo(userId);
+        const avatarUrl = profile.avatar_url;
+        
+        if (!avatarUrl) {
+          setColor(undefined);
+          setLoading(false);
+          return;
+        }
+
+        const httpUrl = mxcUrlToHttp(mx, avatarUrl, useAuthentication);
+        if (!httpUrl) {
+          setColor(undefined);
+          setLoading(false);
+          return;
+        }
+
+        const extractedColor = await fetchAndExtractColor(httpUrl);
+        setColor(extractedColor);
+      } catch (e) {
+        console.error('Failed to load user color from avatar:', e);
+        setColor(undefined);
+      }
+      setLoading(false);
+    };
+
+    loadColor();
+  }, [mx, useAuthentication]);
+
+  const updateColor = useCallback(async (newColor: string | undefined) => {
+    const userId = mx.getUserId();
+    if (!userId) return;
+
+    try {
+      const profile = await mx.getProfileInfo(userId);
+      const avatarUrl = profile.avatar_url;
+
+      if (!avatarUrl) {
+        // No avatar to embed color in
+        console.warn('Cannot set color: no avatar image set');
+        throw new Error('No avatar set');
+      }
+
+      // Fetch current avatar
+      const avatarData = await fetchAvatarData(mx, avatarUrl, useAuthentication);
+      if (!avatarData) {
+        console.error('Failed to fetch current avatar');
+        throw new Error('Failed to fetch avatar');
+      }
+
+      console.log('Original avatar size:', avatarData.byteLength, 'bytes');
+
+      // Modify PNG metadata
+      let newAvatarData: Uint8Array | null;
+      if (newColor) {
+        newAvatarData = embedColorInPNG(avatarData, newColor);
+      } else {
+        newAvatarData = removeColorFromPNG(avatarData);
+      }
+
+      if (!newAvatarData) {
+        console.error('Failed to modify avatar PNG metadata - not a valid PNG?');
+        throw new Error('Failed to modify PNG metadata');
+      }
+
+      console.log('Modified avatar size:', newAvatarData.byteLength, 'bytes');
+
+      // Verify the color was embedded correctly before uploading
+      const verifyColor = extractColorFromPNG(newAvatarData);
+      console.log('Verification - embedded color:', verifyColor);
+      
+      if (newColor && verifyColor !== newColor) {
+        console.error('Color verification failed! Expected:', newColor, 'Got:', verifyColor);
+        throw new Error('Color embedding verification failed');
+      }
+
+      // Upload modified avatar
+      const blob = new Blob([newAvatarData], { type: 'image/png' });
+      const uploadResponse = await mx.uploadContent(blob, {
+        name: 'avatar.png',
+        type: 'image/png',
+      });
+
+      console.log('Uploaded new avatar:', uploadResponse.content_uri);
+
+      // Update profile with new avatar
+      await mx.setAvatarUrl(uploadResponse.content_uri);
+
+      setColor(newColor);
+      console.log('User color updated in avatar:', newColor);
+    } catch (e) {
+      console.error('Failed to update user color in avatar:', e);
+      throw e;
+    }
+  }, [mx, useAuthentication]);
+
+  return [color, updateColor, loading];
+}
+
+// Cache for user colors to avoid refetching for each message
+const userColorCache = new Map<string, { color: string | undefined; timestamp: number }>();
+const CACHE_TTL_MS = 5 * 60 * 1000; // 5 minutes
+
+/**
+ * Hook to get another user's chosen profile color from their avatar metadata
+ * @param userId - The user ID to get color for
+ * @param avatarMxc - The user's avatar MXC URL
+ * @returns The user's chosen color or undefined
+ */
+export function useOtherUserColor(userId: string, avatarMxc: string | undefined): string | undefined {
+  const mx = useMatrixClient();
+  const useAuthentication = useMediaAuthentication();
+  const [color, setColor] = useState<string | undefined>();
+
+  useEffect(() => {
+    if (!avatarMxc) {
+      setColor(undefined);
+      return;
+    }
+
+    // Check cache first
+    const cacheKey = `${userId}:${avatarMxc}`;
+    const cached = userColorCache.get(cacheKey);
+    if (cached && Date.now() - cached.timestamp < CACHE_TTL_MS) {
+      setColor(cached.color);
+      return;
+    }
+
+    const loadColor = async () => {
+      const httpUrl = mxcUrlToHttp(mx, avatarMxc, useAuthentication);
+      if (!httpUrl) {
+        setColor(undefined);
+        return;
+      }
+
+      const extractedColor = await fetchAndExtractColor(httpUrl);
+      
+      // Cache the result
+      userColorCache.set(cacheKey, { color: extractedColor, timestamp: Date.now() });
+      
+      setColor(extractedColor);
+    };
+
+    loadColor();
+  }, [mx, useAuthentication, avatarMxc, userId]);
+
+  return color;
+}
+

src/app/pages/client/inbox/Notifications.tsx

@@ -97,6 +97,7 @@ import {
 } from '../../../hooks/useMemberPowerTag';
 import { useRoomCreatorsTag } from '../../../hooks/useRoomCreatorsTag';
 import { useRoomCreators } from '../../../hooks/useRoomCreators';
+import { useOtherUserColor } from '../../../hooks/useUserColor';
 
 type RoomNotificationsGroup = {
   roomId: string;
@@ -200,6 +201,141 @@ const useNotificationTimeline = (
   return [notificationTimeline, loadTimeline, silentReloadTimeline];
 };
 
+/**
+ * Props for NotificationItem component
+ */
+type NotificationItemProps = {
+  room: Room;
+  notification: INotification;
+  getMemberPowerTag: ReturnType<typeof useGetMemberPowerTag>;
+  accessibleTagColors: Map<string, string> | undefined;
+  renderMatrixEvent: ReturnType<typeof useMatrixEventRenderer<[IRoomEvent, string, GetContentCallback]>>;
+  handleOpenClick: MouseEventHandler;
+  legacyUsernameColor?: boolean;
+  hour24Clock: boolean;
+  dateFormatString: string;
+};
+
+/**
+ * Component to render a single notification item with proper hook usage
+ */
+function NotificationItem({
+  room,
+  notification,
+  getMemberPowerTag,
+  accessibleTagColors,
+  renderMatrixEvent,
+  handleOpenClick,
+  legacyUsernameColor,
+  hour24Clock,
+  dateFormatString,
+}: NotificationItemProps) {
+  const mx = useMatrixClient();
+  const useAuthentication = useMediaAuthentication();
+  const { event } = notification;
+
+  const displayName =
+    getMemberDisplayName(room, event.sender) ??
+    getMxIdLocalPart(event.sender) ??
+    event.sender;
+  const senderAvatarMxc = getMemberAvatarMxc(room, event.sender);
+  const getContent = (() => event.content) as GetContentCallback;
+
+  const relation = event.content['m.relates_to'];
+  const replyEventId = relation?.['m.in_reply_to']?.event_id;
+  const threadRootId =
+    relation?.rel_type === RelationType.Thread ? relation.event_id : undefined;
+
+  // Get custom user color from avatar metadata
+  const customUserColor = useOtherUserColor(event.sender, senderAvatarMxc);
+
+  const memberPowerTag = getMemberPowerTag(event.sender);
+  const tagColor = memberPowerTag?.color
+    ? accessibleTagColors?.get(memberPowerTag.color)
+    : undefined;
+  const tagIconSrc = memberPowerTag?.icon
+    ? getPowerTagIconSrc(mx, useAuthentication, memberPowerTag.icon)
+    : undefined;
+
+  // Priority: custom user color > tag color (non-legacy) > colorMXID (legacy)
+  const usernameColor = customUserColor ?? (legacyUsernameColor ? colorMXID(event.sender) : tagColor);
+
+  return (
+    <SequenceCard
+      key={notification.event.event_id}
+      style={{ padding: config.space.S400 }}
+      variant="SurfaceVariant"
+      direction="Column"
+    >
+      <ModernLayout
+        before={
+          <AvatarBase>
+            <Avatar size="300">
+              <UserAvatar
+                userId={event.sender}
+                src={
+                  senderAvatarMxc
+                    ? mxcUrlToHttp(
+                        mx,
+                        senderAvatarMxc,
+                        useAuthentication,
+                        48,
+                        48,
+                        'crop'
+                      ) ?? undefined
+                    : undefined
+                }
+                alt={displayName}
+                renderFallback={() => <Icon size="200" src={Icons.User} filled />}
+              />
+            </Avatar>
+          </AvatarBase>
+        }
+      >
+        <Box gap="300" justifyContent="SpaceBetween" alignItems="Center" grow="Yes">
+          <Box gap="200" alignItems="Baseline">
+            <Box alignItems="Center" gap="200">
+              <Username style={{ color: usernameColor }}>
+                <Text as="span" truncate>
+                  <UsernameBold>{displayName}</UsernameBold>
+                </Text>
+              </Username>
+              {tagIconSrc && <PowerIcon size="100" iconSrc={tagIconSrc} />}
+            </Box>
+            <Time
+              ts={event.origin_server_ts}
+              hour24Clock={hour24Clock}
+              dateFormatString={dateFormatString}
+            />
+          </Box>
+          <Box shrink="No" gap="200" alignItems="Center">
+            <Chip
+              data-event-id={event.event_id}
+              onClick={handleOpenClick}
+              variant="Secondary"
+              radii="400"
+            >
+              <Text size="T200">Open</Text>
+            </Chip>
+          </Box>
+        </Box>
+        {replyEventId && (
+          <Reply
+            room={room}
+            replyEventId={replyEventId}
+            threadRootId={threadRootId}
+            onClick={handleOpenClick}
+            getMemberPowerTag={getMemberPowerTag}
+            accessibleTagColors={accessibleTagColors}
+            legacyUsernameColor={legacyUsernameColor}
+          />
+        )}
+        {renderMatrixEvent(event.type, false, event, displayName, getContent)}
+      </ModernLayout>
+    </SequenceCard>
+  );
+}
+
 type RoomNotificationsGroupProps = {
   room: Room;
   notifications: INotification[];
@@ -439,106 +575,20 @@ function RoomNotificationsGroupComp({
         </Box>
       </Header>
       <Box direction="Column" gap="100">
-        {notifications.map((notification) => {
+        {notifications.map((notification) => (
-          const { event } = notification;
+          <NotificationItem
-
+            key={notification.event.event_id}
-          const displayName =
+            room={room}
-            getMemberDisplayName(room, event.sender) ??
+            notification={notification}
-            getMxIdLocalPart(event.sender) ??
+            getMemberPowerTag={getMemberPowerTag}
-            event.sender;
+            accessibleTagColors={accessibleTagColors}
-          const senderAvatarMxc = getMemberAvatarMxc(room, event.sender);
+            renderMatrixEvent={renderMatrixEvent}
-          const getContent = (() => event.content) as GetContentCallback;
+            handleOpenClick={handleOpenClick}
-
+            legacyUsernameColor={legacyUsernameColor}
-          const relation = event.content['m.relates_to'];
+            hour24Clock={hour24Clock}
-          const replyEventId = relation?.['m.in_reply_to']?.event_id;
+            dateFormatString={dateFormatString}
-          const threadRootId =
+          />
-            relation?.rel_type === RelationType.Thread ? relation.event_id : undefined;
+        ))}
-
-          const memberPowerTag = getMemberPowerTag(event.sender);
-          const tagColor = memberPowerTag?.color
-            ? accessibleTagColors?.get(memberPowerTag.color)
-            : undefined;
-          const tagIconSrc = memberPowerTag?.icon
-            ? getPowerTagIconSrc(mx, useAuthentication, memberPowerTag.icon)
-            : undefined;
-
-          const usernameColor = legacyUsernameColor ? colorMXID(event.sender) : tagColor;
-
-          return (
-            <SequenceCard
-              key={notification.event.event_id}
-              style={{ padding: config.space.S400 }}
-              variant="SurfaceVariant"
-              direction="Column"
-            >
-              <ModernLayout
-                before={
-                  <AvatarBase>
-                    <Avatar size="300">
-                      <UserAvatar
-                        userId={event.sender}
-                        src={
-                          senderAvatarMxc
-                            ? mxcUrlToHttp(
-                                mx,
-                                senderAvatarMxc,
-                                useAuthentication,
-                                48,
-                                48,
-                                'crop'
-                              ) ?? undefined
-                            : undefined
-                        }
-                        alt={displayName}
-                        renderFallback={() => <Icon size="200" src={Icons.User} filled />}
-                      />
-                    </Avatar>
-                  </AvatarBase>
-                }
-              >
-                <Box gap="300" justifyContent="SpaceBetween" alignItems="Center" grow="Yes">
-                  <Box gap="200" alignItems="Baseline">
-                    <Box alignItems="Center" gap="200">
-                      <Username style={{ color: usernameColor }}>
-                        <Text as="span" truncate>
-                          <UsernameBold>{displayName}</UsernameBold>
-                        </Text>
-                      </Username>
-                      {tagIconSrc && <PowerIcon size="100" iconSrc={tagIconSrc} />}
-                    </Box>
-                    <Time
-                      ts={event.origin_server_ts}
-                      hour24Clock={hour24Clock}
-                      dateFormatString={dateFormatString}
-                    />
-                  </Box>
-                  <Box shrink="No" gap="200" alignItems="Center">
-                    <Chip
-                      data-event-id={event.event_id}
-                      onClick={handleOpenClick}
-                      variant="Secondary"
-                      radii="400"
-                    >
-                      <Text size="T200">Open</Text>
-                    </Chip>
-                  </Box>
-                </Box>
-                {replyEventId && (
-                  <Reply
-                    room={room}
-                    replyEventId={replyEventId}
-                    threadRootId={threadRootId}
-                    onClick={handleOpenClick}
-                    getMemberPowerTag={getMemberPowerTag}
-                    accessibleTagColors={accessibleTagColors}
-                    legacyUsernameColor={legacyUsernameColor}
-                  />
-                )}
-                {renderMatrixEvent(event.type, false, event, displayName, getContent)}
-              </ModernLayout>
-            </SequenceCard>
-          );
-        })}
       </Box>
     </Box>
   );

src/app/utils/pngMetadata.ts

@@ -0,0 +1,306 @@
+/**
+ * Utilities for reading and writing PNG metadata (tEXt chunks)
+ * Used to embed user color in avatar images
+ */
+
+/* eslint-disable no-bitwise */
+/* eslint-disable no-plusplus */
+/* eslint-disable no-restricted-syntax */
+/* eslint-disable no-console */
+
+/** PNG signature bytes */
+const PNG_SIGNATURE = new Uint8Array([137, 80, 78, 71, 13, 10, 26, 10]);
+
+/** Key used to store user color in PNG metadata */
+export const PAARROT_COLOR_KEY = 'paarrot:color';
+
+let crc32Table: Uint32Array | null = null;
+function getCRC32Table(): Uint32Array {
+  if (crc32Table) return crc32Table;
+  
+  crc32Table = new Uint32Array(256);
+  for (let i = 0; i < 256; i++) {
+    let c = i;
+    for (let j = 0; j < 8; j++) {
+      c = (c & 1) ? (0xedb88320 ^ (c >>> 1)) : (c >>> 1);
+    }
+    crc32Table[i] = c;
+  }
+  return crc32Table;
+}
+
+/**
+ * Calculate CRC32 for a chunk
+ */
+function crc32(data: Uint8Array): number {
+  let crc = 0xffffffff;
+  const table = getCRC32Table();
+  
+  for (let i = 0; i < data.length; i++) {
+    crc = (crc >>> 8) ^ table[(crc ^ data[i]) & 0xff];
+  }
+  
+  return (crc ^ 0xffffffff) >>> 0;
+}
+
+/**
+ * Read a 32-bit big-endian integer from a buffer
+ */
+function readUint32BE(data: Uint8Array, offset: number): number {
+  return (data[offset] << 24) | (data[offset + 1] << 16) | (data[offset + 2] << 8) | data[offset + 3];
+}
+
+/**
+ * Write a 32-bit big-endian integer to a buffer
+ */
+function writeUint32BE(value: number): Uint8Array {
+  return new Uint8Array([
+    (value >>> 24) & 0xff,
+    (value >>> 16) & 0xff,
+    (value >>> 8) & 0xff,
+    value & 0xff,
+  ]);
+}
+
+/**
+ * Create a tEXt chunk with the given key and value
+ */
+function createTextChunk(key: string, value: string): Uint8Array {
+  const keyBytes = new TextEncoder().encode(key);
+  const valueBytes = new TextEncoder().encode(value);
+  
+  // tEXt chunk data: key + null byte + value
+  const chunkData = new Uint8Array(keyBytes.length + 1 + valueBytes.length);
+  chunkData.set(keyBytes, 0);
+  chunkData[keyBytes.length] = 0; // null separator
+  chunkData.set(valueBytes, keyBytes.length + 1);
+  
+  const chunkType = new TextEncoder().encode('tEXt');
+  
+  // Calculate CRC over type + data
+  const crcData = new Uint8Array(4 + chunkData.length);
+  crcData.set(chunkType, 0);
+  crcData.set(chunkData, 4);
+  const crc = crc32(crcData);
+  
+  // Full chunk: length (4) + type (4) + data + crc (4)
+  const chunk = new Uint8Array(4 + 4 + chunkData.length + 4);
+  chunk.set(writeUint32BE(chunkData.length), 0);
+  chunk.set(chunkType, 4);
+  chunk.set(chunkData, 8);
+  chunk.set(writeUint32BE(crc), 8 + chunkData.length);
+  
+  return chunk;
+}
+
+/**
+ * Parse PNG chunks from image data
+ */
+function parseChunks(data: Uint8Array): Array<{ type: string; data: Uint8Array; offset: number; length: number }> {
+  const chunks: Array<{ type: string; data: Uint8Array; offset: number; length: number }> = [];
+  let offset = 8; // Skip PNG signature
+  
+  while (offset < data.length) {
+    const length = readUint32BE(data, offset);
+    const type = new TextDecoder().decode(data.slice(offset + 4, offset + 8));
+    const chunkData = data.slice(offset + 8, offset + 8 + length);
+    
+    chunks.push({
+      type,
+      data: chunkData,
+      offset,
+      length: 12 + length, // length field + type + data + crc
+    });
+    
+    offset += 12 + length;
+    
+    if (type === 'IEND') break;
+  }
+  
+  return chunks;
+}
+
+/**
+ * Read a tEXt chunk value
+ */
+function parseTextChunk(data: Uint8Array): { key: string; value: string } | null {
+  const nullIndex = data.indexOf(0);
+  if (nullIndex === -1) return null;
+  
+  const key = new TextDecoder().decode(data.slice(0, nullIndex));
+  const value = new TextDecoder().decode(data.slice(nullIndex + 1));
+  
+  return { key, value };
+}
+
+/**
+ * Extract paarrot color from PNG image data
+ * @param imageData - Raw PNG image data as ArrayBuffer or Uint8Array
+ * @returns The color string if found, or undefined
+ */
+export function extractColorFromPNG(imageData: ArrayBuffer | Uint8Array): string | undefined {
+  const data = imageData instanceof Uint8Array ? imageData : new Uint8Array(imageData);
+  
+  console.log('[extractColorFromPNG] Input size:', data.length, 'bytes');
+  
+  // Verify PNG signature
+  for (let i = 0; i < 8; i++) {
+    if (data[i] !== PNG_SIGNATURE[i]) {
+      console.error('[extractColorFromPNG] Not a PNG! Byte', i, 'is', data[i], 'expected', PNG_SIGNATURE[i]);
+      return undefined; // Not a PNG
+    }
+  }
+  
+  const chunks = parseChunks(data);
+  console.log('[extractColorFromPNG] Found', chunks.length, 'chunks:', chunks.map(c => c.type).join(', '));
+  
+  for (const chunk of chunks) {
+    if (chunk.type === 'tEXt') {
+      const text = parseTextChunk(chunk.data);
+      console.log('[extractColorFromPNG] tEXt chunk found, key:', text?.key);
+      if (text && text.key === PAARROT_COLOR_KEY) {
+        console.log('[extractColorFromPNG] Found color:', text.value);
+        return text.value;
+      }
+    }
+  }
+  
+  console.log('[extractColorFromPNG] No color found');
+  return undefined;
+}
+
+/**
+ * Embed paarrot color into PNG image data
+ * @param imageData - Raw PNG image data as ArrayBuffer or Uint8Array
+ * @param color - The color string to embed (e.g., '#ff5500')
+ * @returns New PNG data with embedded color, or null if not a valid PNG
+ */
+export function embedColorInPNG(imageData: ArrayBuffer | Uint8Array, color: string): Uint8Array | null {
+  const data = imageData instanceof Uint8Array ? imageData : new Uint8Array(imageData);
+  
+  console.log('[embedColorInPNG] Input size:', data.length, 'bytes');
+  console.log('[embedColorInPNG] First 8 bytes:', Array.from(data.slice(0, 8)));
+  console.log('[embedColorInPNG] PNG signature expected:', Array.from(PNG_SIGNATURE));
+  
+  // Verify PNG signature
+  for (let i = 0; i < 8; i++) {
+    if (data[i] !== PNG_SIGNATURE[i]) {
+      console.error('[embedColorInPNG] Not a PNG! Byte', i, 'is', data[i], 'expected', PNG_SIGNATURE[i]);
+      return null; // Not a PNG
+    }
+  }
+  
+  console.log('[embedColorInPNG] PNG signature verified OK');
+  
+  const chunks = parseChunks(data);
+  console.log('[embedColorInPNG] Found', chunks.length, 'chunks:', chunks.map(c => c.type).join(', '));
+  
+  // Find IHDR chunk (always first) and any existing paarrot tEXt chunk
+  let insertOffset = 8; // After signature
+  let existingPaarrotChunk: { offset: number; length: number } | null = null;
+  
+  for (const chunk of chunks) {
+    if (chunk.type === 'IHDR') {
+      insertOffset = chunk.offset + chunk.length; // Insert after IHDR
+    } else if (chunk.type === 'tEXt') {
+      const text = parseTextChunk(chunk.data);
+      if (text && text.key === PAARROT_COLOR_KEY) {
+        existingPaarrotChunk = { offset: chunk.offset, length: chunk.length };
+      }
+    }
+  }
+  
+  // Create new tEXt chunk with color
+  const colorChunk = createTextChunk(PAARROT_COLOR_KEY, color);
+  console.log('[embedColorInPNG] Created color chunk, size:', colorChunk.length, 'bytes');
+  console.log('[embedColorInPNG] Color being embedded:', color);
+  
+  // Build new PNG data
+  let newData: Uint8Array;
+  
+  if (existingPaarrotChunk) {
+    // Replace existing chunk
+    console.log('[embedColorInPNG] Replacing existing chunk at offset', existingPaarrotChunk.offset);
+    newData = new Uint8Array(data.length - existingPaarrotChunk.length + colorChunk.length);
+    newData.set(data.slice(0, existingPaarrotChunk.offset), 0);
+    newData.set(colorChunk, existingPaarrotChunk.offset);
+    newData.set(
+      data.slice(existingPaarrotChunk.offset + existingPaarrotChunk.length),
+      existingPaarrotChunk.offset + colorChunk.length
+    );
+  } else {
+    // Insert new chunk after IHDR
+    console.log('[embedColorInPNG] Inserting new chunk at offset', insertOffset);
+    newData = new Uint8Array(data.length + colorChunk.length);
+    newData.set(data.slice(0, insertOffset), 0);
+    newData.set(colorChunk, insertOffset);
+    newData.set(data.slice(insertOffset), insertOffset + colorChunk.length);
+  }
+  
+  console.log('[embedColorInPNG] Output size:', newData.length, 'bytes');
+  
+  return newData;
+}
+
+/**
+ * Remove paarrot color from PNG image data
+ * @param imageData - Raw PNG image data as ArrayBuffer or Uint8Array
+ * @returns New PNG data without the color chunk, or null if not a valid PNG
+ */
+export function removeColorFromPNG(imageData: ArrayBuffer | Uint8Array): Uint8Array | null {
+  const data = imageData instanceof Uint8Array ? imageData : new Uint8Array(imageData);
+  
+  // Verify PNG signature
+  for (let i = 0; i < 8; i++) {
+    if (data[i] !== PNG_SIGNATURE[i]) {
+      return null; // Not a PNG
+    }
+  }
+  
+  const chunks = parseChunks(data);
+  
+  // Find existing paarrot tEXt chunk
+  let existingPaarrotChunk: { offset: number; length: number } | null = null;
+  
+  for (const chunk of chunks) {
+    if (chunk.type === 'tEXt') {
+      const text = parseTextChunk(chunk.data);
+      if (text && text.key === PAARROT_COLOR_KEY) {
+        existingPaarrotChunk = { offset: chunk.offset, length: chunk.length };
+        break;
+      }
+    }
+  }
+  
+  if (!existingPaarrotChunk) {
+    // No color to remove
+    return data;
+  }
+  
+  // Build new PNG data without the color chunk
+  const newData = new Uint8Array(data.length - existingPaarrotChunk.length);
+  newData.set(data.slice(0, existingPaarrotChunk.offset), 0);
+  newData.set(
+    data.slice(existingPaarrotChunk.offset + existingPaarrotChunk.length),
+    existingPaarrotChunk.offset
+  );
+  
+  return newData;
+}
+
+/**
+ * Fetch an image and extract the paarrot color from it
+ * @param url - The URL of the image to fetch
+ * @returns The color string if found, or undefined
+ */
+export async function fetchAndExtractColor(url: string): Promise<string | undefined> {
+  try {
+    const response = await fetch(url);
+    if (!response.ok) return undefined;
+    
+    const arrayBuffer = await response.arrayBuffer();
+    return extractColorFromPNG(arrayBuffer);
+  } catch {
+    return undefined;
+  }
+}