diff --git a/lib/model/content.dart b/lib/model/content.dart
index 358a02feb1..20346c6f63 100644
--- a/lib/model/content.dart
+++ b/lib/model/content.dart
@@ -1097,8 +1097,8 @@ class UserMentionNode extends MentionNode {
 
   /// The ID of the user being mentioned.
   ///
-  /// This is null for wildcard mentions
-  /// or when the user ID is unavailable in the HTML (e.g., legacy mentions).
+  /// This is null when the user ID is unavailable in the HTML,
+  /// e.g., when the mention is a legacy user mention.
   final int? userId;
 
   @override
@@ -1129,7 +1129,13 @@ class UserGroupMentionNode extends MentionNode {
   }
 }
 
-// TODO(#646) add WildcardMentionNode
+class WildcardMentionNode extends MentionNode {
+  const WildcardMentionNode({
+    super.debugHtmlNode,
+    required super.nodes,
+    required super.isSilent,
+  });
+}
 
 sealed class EmojiNode extends InlineContentNode {
   const EmojiNode({super.debugHtmlNode});
@@ -1369,29 +1375,35 @@ class _ZulipInlineContentParser {
     //   tighter on a MentionNode's contents overall.
     final nodes = parseInlineContentList(element.nodes);
 
-    if (mentionType case 'user-group-mention') {
-      final userGroupId = int.tryParse(
-        element.attributes['data-user-group-id'] ?? '',
-        radix: 10);
-      if (userGroupId == null) {
+    switch ((mentionType, element.attributes['data-user-id'])) {
+      case ('user-group-mention', _):
+        final userGroupId = int.tryParse(
+          element.attributes['data-user-group-id'] ?? '',
+          radix: 10);
+        if (userGroupId == null) {
+          return null;
+        }
+        return UserGroupMentionNode(
+          nodes: nodes,
+          isSilent: isSilent,
+          userGroupId: userGroupId,
+          debugHtmlNode: debugHtmlNode);
+      case ('topic-mention', _):
+      case ('user-mention', _) when hasChannelWildcardClass:
+      case ('user-mention', '*'): // legacy channel wildcard
+        return WildcardMentionNode(
+          nodes: nodes,
+          isSilent: isSilent,
+          debugHtmlNode: debugHtmlNode);
+      case ('user-mention', final userIdString):
+        final userId = int.tryParse(userIdString ?? '', radix: 10);
+        return UserMentionNode(
+          nodes: nodes,
+          isSilent: isSilent,
+          userId: userId,
+          debugHtmlNode: debugHtmlNode);
+      case _:
         return null;
-      }
-      return UserGroupMentionNode(
-        nodes: nodes,
-        isSilent: isSilent,
-        userGroupId: userGroupId,
-        debugHtmlNode: debugHtmlNode);
-    } else {
-      final userId = switch (element.attributes['data-user-id']) {
-        // For legacy or wildcard mentions.
-        null || '*' => null,
-        final userIdString => int.tryParse(userIdString, radix: 10),
-      };
-      return UserMentionNode(
-        nodes: nodes,
-        isSilent: isSilent,
-        userId: userId,
-        debugHtmlNode: debugHtmlNode);
     }
   }
 
diff --git a/lib/widgets/content.dart b/lib/widgets/content.dart
index 297b77894a..8fd4a86e03 100644
--- a/lib/widgets/content.dart
+++ b/lib/widgets/content.dart
@@ -43,6 +43,7 @@ class ContentTheme extends ThemeExtension<ContentTheme> {
     return ContentTheme._(
       colorCodeBlockBackground: const HSLColor.fromAHSL(0.04, 0, 0, 0).toColor(),
       colorDirectMentionBackground: const HSLColor.fromAHSL(0.2, 240, 0.7, 0.7).toColor(),
+      colorGroupMentionBackground: const HSLColor.fromAHSL(0.18, 183, 0.6, 0.45).toColor(),
       colorGlobalTimeBackground: const HSLColor.fromAHSL(1, 0, 0, 0.93).toColor(),
       colorGlobalTimeBorder: const HSLColor.fromAHSL(1, 0, 0, 0.8).toColor(),
       colorLink: const HSLColor.fromAHSL(1, 200, 1, 0.4).toColor(),
@@ -77,6 +78,7 @@ class ContentTheme extends ThemeExtension<ContentTheme> {
     return ContentTheme._(
       colorCodeBlockBackground: const HSLColor.fromAHSL(0.04, 0, 0, 1).toColor(),
       colorDirectMentionBackground: const HSLColor.fromAHSL(0.25, 240, 0.52, 0.6).toColor(),
+      colorGroupMentionBackground: const HSLColor.fromAHSL(0.20, 183, 0.52, 0.4).toColor(),
       colorGlobalTimeBackground: const HSLColor.fromAHSL(0.2, 0, 0, 0).toColor(),
       colorGlobalTimeBorder: const HSLColor.fromAHSL(0.4, 0, 0, 0).toColor(),
       colorLink: const HSLColor.fromAHSL(1, 200, 1, 0.4).toColor(), // the same as light in Web
@@ -110,6 +112,7 @@ class ContentTheme extends ThemeExtension<ContentTheme> {
   ContentTheme._({
     required this.colorCodeBlockBackground,
     required this.colorDirectMentionBackground,
+    required this.colorGroupMentionBackground,
     required this.colorGlobalTimeBackground,
     required this.colorGlobalTimeBorder,
     required this.colorLink,
@@ -143,6 +146,7 @@ class ContentTheme extends ThemeExtension<ContentTheme> {
 
   final Color colorCodeBlockBackground;
   final Color colorDirectMentionBackground;
+  final Color colorGroupMentionBackground;
   final Color colorGlobalTimeBackground;
   final Color colorGlobalTimeBorder;
   final Color colorLink;
@@ -204,6 +208,7 @@ class ContentTheme extends ThemeExtension<ContentTheme> {
   ContentTheme copyWith({
     Color? colorCodeBlockBackground,
     Color? colorDirectMentionBackground,
+    Color? colorGroupMentionBackground,
     Color? colorGlobalTimeBackground,
     Color? colorGlobalTimeBorder,
     Color? colorLink,
@@ -227,6 +232,7 @@ class ContentTheme extends ThemeExtension<ContentTheme> {
     return ContentTheme._(
       colorCodeBlockBackground: colorCodeBlockBackground ?? this.colorCodeBlockBackground,
       colorDirectMentionBackground: colorDirectMentionBackground ?? this.colorDirectMentionBackground,
+      colorGroupMentionBackground: colorGroupMentionBackground ?? this.colorGroupMentionBackground,
       colorGlobalTimeBackground: colorGlobalTimeBackground ?? this.colorGlobalTimeBackground,
       colorGlobalTimeBorder: colorGlobalTimeBorder ?? this.colorGlobalTimeBorder,
       colorLink: colorLink ?? this.colorLink,
@@ -257,6 +263,7 @@ class ContentTheme extends ThemeExtension<ContentTheme> {
     return ContentTheme._(
       colorCodeBlockBackground: Color.lerp(colorCodeBlockBackground, other.colorCodeBlockBackground, t)!,
       colorDirectMentionBackground: Color.lerp(colorDirectMentionBackground, other.colorDirectMentionBackground, t)!,
+      colorGroupMentionBackground: Color.lerp(colorGroupMentionBackground, other.colorGroupMentionBackground, t)!,
       colorGlobalTimeBackground: Color.lerp(colorGlobalTimeBackground, other.colorGlobalTimeBackground, t)!,
       colorGlobalTimeBorder: Color.lerp(colorGlobalTimeBorder, other.colorGlobalTimeBorder, t)!,
       colorLink: Color.lerp(colorLink, other.colorLink, t)!,
@@ -1220,12 +1227,18 @@ class Mention extends StatelessWidget {
           nodes = [TextNode(node.isSilent ? fullName : '@$fullName')];
         }
       case UserMentionNode(userId: null):
+      case WildcardMentionNode():
     }
 
+    final backgroundPillColor = switch (node) {
+      UserMentionNode() => contentTheme.colorDirectMentionBackground,
+      UserGroupMentionNode() || WildcardMentionNode()
+        => contentTheme.colorGroupMentionBackground,
+    };
+
     return Container(
       decoration: BoxDecoration(
-        // TODO(#646) different for wildcard mentions
-        color: contentTheme.colorDirectMentionBackground,
+        color: backgroundPillColor,
         borderRadius: const BorderRadius.all(Radius.circular(3))),
       padding: const EdgeInsets.symmetric(horizontal: 0.2 * kBaseFontSize),
       child: InlineContent(
@@ -1235,8 +1248,7 @@ class Mention extends StatelessWidget {
         // (The parser on creating a MentionNode has a TODO to check that.)
         linkRecognizers: null,
 
-        // TODO(#647) when self-user is non-silently mentioned, make bold, and:
-        // TODO(#646) distinguish font color between direct and wildcard mentions
+        // TODO(#647) when self-user is mentioned, make bold, and change font color.
         style: ambientTextStyle,
 
         nodes: nodes));
diff --git a/test/model/content_test.dart b/test/model/content_test.dart
index b5da630f7e..09d29cdee7 100644
--- a/test/model/content_test.dart
+++ b/test/model/content_test.dart
@@ -127,6 +127,15 @@ class ContentExample {
     '<p><span class="silent user-mention" data-user-id="2187">Greg Price</span></p>',
     const UserMentionNode(nodes: [TextNode('Greg Price')], isSilent: true, userId: 2187));
 
+  // No silent version of this form, because silent mentions were new
+  // in zulip/zulip#11221, long after this legacy form was removed.
+  static final legacyUserMention = ContentExample.inline(
+    'legacy user @-mention',
+    "@**Greg Price**", // (before 2017-01)
+    expectedText: '@Greg Price',
+    '<p><span class="user-mention" data-user-email="email@example.com">@Greg Price</span></p>',
+    const UserMentionNode(nodes: [TextNode('@Greg Price')], isSilent: false, userId: null));
+
   static final groupMentionPlain = ContentExample.inline(
     'plain group @-mention',
     "@*test-empty*",
@@ -153,63 +162,63 @@ class ContentExample {
     "@**all**",
     expectedText: '@all',
     '<p><span class="user-mention channel-wildcard-mention" data-user-id="*">@all</span></p>',
-    const UserMentionNode(nodes: [TextNode('@all')], isSilent: false, userId: null));
+    const WildcardMentionNode(nodes: [TextNode('@all')], isSilent: false));
 
   static final channelWildcardMentionSilent = ContentExample.inline(
     'silent channel wildcard @-mention',
     "@_**everyone**",
     expectedText: 'everyone',
     '<p><span class="user-mention channel-wildcard-mention silent" data-user-id="*">everyone</span></p>',
-    const UserMentionNode(nodes: [TextNode('everyone')], isSilent: true, userId: null));
+    const WildcardMentionNode(nodes: [TextNode('everyone')], isSilent: true));
 
   static final channelWildcardMentionSilentClassOrderReversed = ContentExample.inline(
     'silent channel wildcard @-mention, class order reversed',
     "@_**channel**", // (hypothetical server variation)
     expectedText: 'channel',
     '<p><span class="silent user-mention channel-wildcard-mention" data-user-id="*">channel</span></p>',
-    const UserMentionNode(nodes: [TextNode('channel')], isSilent: true, userId: null));
+    const WildcardMentionNode(nodes: [TextNode('channel')], isSilent: true));
 
   static final legacyChannelWildcardMentionPlain = ContentExample.inline(
     'legacy plain channel wildcard @-mention',
     "@**channel**",
     expectedText: '@channel',
     '<p><span class="user-mention" data-user-id="*">@channel</span></p>',
-    const UserMentionNode(nodes: [TextNode('@channel')], isSilent: false, userId: null));
+    const WildcardMentionNode(nodes: [TextNode('@channel')], isSilent: false));
 
   static final legacyChannelWildcardMentionSilent = ContentExample.inline(
     'legacy silent channel wildcard @-mention',
     "@_**stream**",
     expectedText: 'stream',
     '<p><span class="user-mention silent" data-user-id="*">stream</span></p>',
-    const UserMentionNode(nodes: [TextNode('stream')], isSilent: true, userId: null));
+    const WildcardMentionNode(nodes: [TextNode('stream')], isSilent: true));
 
   static final legacyChannelWildcardMentionSilentClassOrderReversed = ContentExample.inline(
     'legacy silent channel wildcard @-mention, class order reversed',
     "@_**all**", // (hypothetical server variation)
     expectedText: 'all',
     '<p><span class="silent user-mention" data-user-id="*">all</span></p>',
-    const UserMentionNode(nodes: [TextNode('all')], isSilent: true, userId: null));
+    const WildcardMentionNode(nodes: [TextNode('all')], isSilent: true));
 
   static final topicMentionPlain = ContentExample.inline(
     'plain @-topic',
     "@**topic**",
     expectedText: '@topic',
     '<p><span class="topic-mention">@topic</span></p>',
-    const UserMentionNode(nodes: [TextNode('@topic')], isSilent: false, userId: null));
+    const WildcardMentionNode(nodes: [TextNode('@topic')], isSilent: false));
 
   static final topicMentionSilent = ContentExample.inline(
     'silent @-topic',
     "@_**topic**",
     expectedText: 'topic',
     '<p><span class="topic-mention silent">topic</span></p>',
-    const UserMentionNode(nodes: [TextNode('topic')], isSilent: true, userId: null));
+    const WildcardMentionNode(nodes: [TextNode('topic')], isSilent: true));
 
   static final topicMentionSilentClassOrderReversed = ContentExample.inline(
     'silent @-topic, class order reversed',
     "@_**topic**", // (hypothetical server variation)
     expectedText: 'topic',
     '<p><span class="silent topic-mention">topic</span></p>',
-    const UserMentionNode(nodes: [TextNode('topic')], isSilent: true, userId: null));
+    const WildcardMentionNode(nodes: [TextNode('topic')], isSilent: true));
 
   static final emojiUnicode = ContentExample.inline(
     'Unicode emoji, encoded in span element',
@@ -1868,6 +1877,8 @@ void main() async {
     testParseExample(ContentExample.userMentionSilent);
     testParseExample(ContentExample.userMentionSilentClassOrderReversed);
 
+    testParseExample(ContentExample.legacyUserMention);
+
     testParseExample(ContentExample.groupMentionPlain);
     testParseExample(ContentExample.groupMentionSilent);
     testParseExample(ContentExample.groupMentionSilentClassOrderReversed);
diff --git a/test/widgets/content_test.dart b/test/widgets/content_test.dart
index dafa30f02b..ff182a7c41 100644
--- a/test/widgets/content_test.dart
+++ b/test/widgets/content_test.dart
@@ -5,6 +5,7 @@ import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter_checks/flutter_checks.dart';
 import 'package:flutter_test/flutter_test.dart';
+import 'package:legacy_checks/legacy_checks.dart';
 import 'package:url_launcher/url_launcher.dart';
 import 'package:zulip/api/model/initial_snapshot.dart';
 import 'package:zulip/api/model/model.dart';
@@ -985,10 +986,16 @@ void main() {
       wrapWithPerAccountStoreWidget: true);
     testContentSmoke(ContentExample.userMentionSilent,
       wrapWithPerAccountStoreWidget: true);
+    testContentSmoke(ContentExample.userMentionSilentClassOrderReversed,
+      wrapWithPerAccountStoreWidget: true);
+    testContentSmoke(ContentExample.legacyUserMention,
+      wrapWithPerAccountStoreWidget: true);
     testContentSmoke(ContentExample.groupMentionPlain,
       wrapWithPerAccountStoreWidget: true);
     testContentSmoke(ContentExample.groupMentionSilent,
       wrapWithPerAccountStoreWidget: true);
+    testContentSmoke(ContentExample.groupMentionSilentClassOrderReversed,
+      wrapWithPerAccountStoreWidget: true);
     testContentSmoke(ContentExample.channelWildcardMentionPlain,
       wrapWithPerAccountStoreWidget: true);
     testContentSmoke(ContentExample.channelWildcardMentionSilent,
@@ -1066,6 +1073,44 @@ void main() {
     //  testFontWeight('non-silent self-user mention in bold context',
     //    expectedWght: 800, // [etc.]
 
+    group('pill color', () {
+      Future<void> checkPillColor(WidgetTester tester, {
+        required String html,
+        required Color Function(ContentTheme) expectColor,
+      }) async {
+        await prepareContent(tester,
+          wrapWithPerAccountStoreWidget: true,
+          plainContent(html));
+
+        final renderObject = tester.renderObject<RenderBox>(find.byType(Mention));
+        final paintBounds = renderObject.paintBounds;
+        final contentTheme = ContentTheme.of(tester.element(find.byType(Mention)));
+
+        check(renderObject).legacyMatcher(equals(paints..rrect(
+          rrect: RRect.fromRectAndRadius(paintBounds, const Radius.circular(3)),
+          style: .fill,
+          color: expectColor(contentTheme))));
+      }
+
+      testWidgets('user mention', (tester) async {
+        await checkPillColor(tester,
+          html: ContentExample.userMentionPlain.html,
+          expectColor: (theme) => theme.colorDirectMentionBackground);
+      });
+
+      testWidgets('user group mention', (tester) async {
+        await checkPillColor(tester,
+          html: ContentExample.groupMentionPlain.html,
+          expectColor: (theme) => theme.colorGroupMentionBackground);
+      });
+
+      testWidgets('wildcard mention', (tester) async {
+        await checkPillColor(tester,
+          html: ContentExample.channelWildcardMentionPlain.html,
+          expectColor: (theme) => theme.colorGroupMentionBackground);
+      });
+    });
+
     group('user mention dynamic name resolution', () {
       Future<void> prepare({
         required WidgetTester tester,
@@ -1098,8 +1143,8 @@ void main() {
       testWidgets('falls back to original text when userId is null', (tester) async {
         await prepare(
           tester: tester,
-          html: '<p><span class="user-mention channel-wildcard-mention" data-user-id="*">@all</span></p>');
-        check(find.text('@all')).findsOne();
+          html: '<p><span class="user-mention" data-user-email="email@example.com">@Greg Price</span></p>');
+        check(find.text('@Greg Price')).findsOne();
       });
 
       testWidgets('handles silent mentions correctly', (tester) async {