diff --git a/packages/flutter/lib/src/services/message_codecs.dart b/packages/flutter/lib/src/services/message_codecs.dart
index e1784c5223..92f9d722e8 100644
--- a/packages/flutter/lib/src/services/message_codecs.dart
+++ b/packages/flutter/lib/src/services/message_codecs.dart
@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-
 import 'dart:convert';
 import 'dart:typed_data';
 
diff --git a/packages/flutter/lib/src/widgets/modal_barrier.dart b/packages/flutter/lib/src/widgets/modal_barrier.dart
index 3d1b693785..31538bdcf6 100644
--- a/packages/flutter/lib/src/widgets/modal_barrier.dart
+++ b/packages/flutter/lib/src/widgets/modal_barrier.dart
@@ -8,7 +8,6 @@ import 'package:flutter/rendering.dart';
 import 'package:flutter/services.dart';
 
 import 'basic.dart';
-import 'container.dart';
 import 'debug.dart';
 import 'framework.dart';
 import 'gesture_detector.dart';
@@ -113,10 +112,8 @@ class ModalBarrier extends StatelessWidget {
               opaque: true,
               child: ConstrainedBox(
                 constraints: const BoxConstraints.expand(),
-                child: color == null ? null : DecoratedBox(
-                  decoration: BoxDecoration(
-                    color: color,
-                  ),
+                child: color == null ? null : ColoredBox(
+                  color: color!,
                 ),
               ),
             ),
diff --git a/packages/flutter/lib/src/widgets/navigator.dart b/packages/flutter/lib/src/widgets/navigator.dart
index 88bae80072..deef670448 100644
--- a/packages/flutter/lib/src/widgets/navigator.dart
+++ b/packages/flutter/lib/src/widgets/navigator.dart
@@ -399,20 +399,30 @@ abstract class Route<T> {
   ///
   /// See also:
   ///
-  ///  * [changedExternalState], which is called when the [Navigator] rebuilds.
+  ///  * [changedExternalState], which is called when the [Navigator] has
+  ///    updated in some manner that might affect the routes.
   @protected
   @mustCallSuper
   void changedInternalState() { }
 
-  /// Called whenever the [Navigator] has its widget rebuilt, to indicate that
-  /// the route may wish to rebuild as well.
+  /// Called whenever the [Navigator] has updated in some manner that might
+  /// affect routes, to indicate that the route may wish to rebuild as well.
   ///
-  /// This is called by the [Navigator] whenever the [NavigatorState]'s
-  /// [State.widget] changes, for example because the [MaterialApp] has been rebuilt.
-  /// This ensures that routes that directly refer to the state of the widget
-  /// that built the [MaterialApp] will be notified when that widget rebuilds,
-  /// since it would otherwise be difficult to notify the routes that state they
-  /// depend on may have changed.
+  /// This is called by the [Navigator] whenever the
+  /// [NavigatorState]'s [State.widget] changes (as in [State.didUpdateWidget]),
+  /// for example because the [MaterialApp] has been rebuilt. This
+  /// ensures that routes that directly refer to the state of the
+  /// widget that built the [MaterialApp] will be notified when that
+  /// widget rebuilds, since it would otherwise be difficult to notify
+  /// the routes that state they depend on may have changed.
+  ///
+  /// It is also called whenever the [Navigator]'s dependencies change
+  /// (as in [State.didChangeDependencies]). This allows routes to use the
+  /// [Navigator]'s context ([NavigatorState.context]), for example in
+  /// [ModalRoute.barrierColor], and update accordingly.
+  ///
+  /// The [ModalRoute] subclass overrides this to force the barrier
+  /// overlay to rebuild.
   ///
   /// See also:
   ///
@@ -3442,6 +3452,8 @@ class NavigatorState extends State<Navigator> with TickerProviderStateMixin, Res
   void didChangeDependencies() {
     super.didChangeDependencies();
     _updateHeroController(HeroControllerScope.of(context));
+    for (final _RouteEntry entry in _history)
+      entry.route.changedExternalState();
   }
 
   void _updateHeroController(HeroController? newHeroController) {
diff --git a/packages/flutter/lib/src/widgets/routes.dart b/packages/flutter/lib/src/widgets/routes.dart
index 17ef544e8f..dc41b755ff 100644
--- a/packages/flutter/lib/src/widgets/routes.dart
+++ b/packages/flutter/lib/src/widgets/routes.dart
@@ -871,15 +871,14 @@ abstract class ModalRoute<T> extends TransitionRoute<T> with LocalHistoryRoute<T
   /// Creates a route that blocks interaction with previous routes.
   ModalRoute({
     RouteSettings? settings,
-    ui.ImageFilter? filter,
-  }) : _filter = filter,
-       super(settings: settings);
+    this.filter,
+  }) : super(settings: settings);
 
   /// The filter to add to the barrier.
   ///
   /// If given, this filter will be applied to the modal barrier using
   /// [BackdropFilter]. This allows blur effects, for example.
-  final ui.ImageFilter? _filter;
+  final ui.ImageFilter? filter;
 
   // The API for general users of this class
 
@@ -1130,9 +1129,14 @@ abstract class ModalRoute<T> extends TransitionRoute<T> with LocalHistoryRoute<T
   ///
   /// If [barrierDismissible] is false, then tapping the barrier has no effect.
   ///
-  /// If this getter would ever start returning a different value, the
-  /// [Route.changedInternalState] should be invoked so that the change can take
-  /// effect.
+  /// If this getter would ever start returning a different value,
+  /// either [changedInternalState] or [changedExternalState] should
+  /// be invoked so that the change can take effect.
+  ///
+  /// It is safe to use `navigator.context` to look up inherited
+  /// widgets here, because the [Navigator] calls
+  /// [changedExternalState] whenever its dependencies change, and
+  /// [changedExternalState] causes the modal barrier to rebuild.
   ///
   /// See also:
   ///
@@ -1154,6 +1158,15 @@ abstract class ModalRoute<T> extends TransitionRoute<T> with LocalHistoryRoute<T
   /// If [semanticsDismissible] is false, then modal barrier semantics are
   /// excluded from the semantics tree and tapping on the modal barrier
   /// has no effect.
+  ///
+  /// If this getter would ever start returning a different value,
+  /// either [changedInternalState] or [changedExternalState] should
+  /// be invoked so that the change can take effect.
+  ///
+  /// It is safe to use `navigator.context` to look up inherited
+  /// widgets here, because the [Navigator] calls
+  /// [changedExternalState] whenever its dependencies change, and
+  /// [changedExternalState] causes the modal barrier to rebuild.
   bool get semanticsDismissible => true;
 
   /// {@template flutter.widgets.ModalRoute.barrierColor}
@@ -1174,22 +1187,24 @@ abstract class ModalRoute<T> extends TransitionRoute<T> with LocalHistoryRoute<T
   /// transparent to the specified color.
   /// {@endtemplate}
   ///
-  /// If this getter would ever start returning a different color, the
-  /// [Route.changedInternalState] should be invoked so that the change can take
-  /// effect.
+  /// If this getter would ever start returning a different color, one
+  /// of the [changedInternalState] or [changedExternalState] methods
+  /// should be invoked so that the change can take effect.
+  ///
+  /// It is safe to use `navigator.context` to look up inherited
+  /// widgets here, because the [Navigator] calls
+  /// [changedExternalState] whenever its dependencies change, and
+  /// [changedExternalState] causes the modal barrier to rebuild.
   ///
   /// {@tool snippet}
   ///
-  /// It is safe to use `navigator.context` here. For example, to make
-  /// the barrier color use the theme's background color, one could say:
+  /// For example, to make the barrier color use the theme's
+  /// background color, one could say:
   ///
   /// ```dart
   /// Color get barrierColor => Theme.of(navigator.context).backgroundColor;
   /// ```
   ///
-  /// The [Navigator] causes the [ModalRoute]'s modal barrier overlay entry
-  /// to rebuild any time its dependencies change.
-  ///
   /// {@end-tool}
   ///
   /// See also:
@@ -1213,9 +1228,14 @@ abstract class ModalRoute<T> extends TransitionRoute<T> with LocalHistoryRoute<T
   /// usually darkened by the modal barrier.
   /// {@endtemplate}
   ///
-  /// If this getter would ever start returning a different label, the
-  /// [Route.changedInternalState] should be invoked so that the change can take
-  /// effect.
+  /// If this getter would ever start returning a different label,
+  /// either [changedInternalState] or [changedExternalState] should
+  /// be invoked so that the change can take effect.
+  ///
+  /// It is safe to use `navigator.context` to look up inherited
+  /// widgets here, because the [Navigator] calls
+  /// [changedExternalState] whenever its dependencies change, and
+  /// [changedExternalState] causes the modal barrier to rebuild.
   ///
   /// See also:
   ///
@@ -1236,9 +1256,14 @@ abstract class ModalRoute<T> extends TransitionRoute<T> with LocalHistoryRoute<T
   /// While the route is animating into position, the color is animated from
   /// transparent to the specified [barrierColor].
   ///
-  /// If this getter would ever start returning a different curve, the
-  /// [changedInternalState] should be invoked so that the change can take
-  /// effect.
+  /// If this getter would ever start returning a different curve,
+  /// either [changedInternalState] or [changedExternalState] should
+  /// be invoked so that the change can take effect.
+  ///
+  /// It is safe to use `navigator.context` to look up inherited
+  /// widgets here, because the [Navigator] calls
+  /// [changedExternalState] whenever its dependencies change, and
+  /// [changedExternalState] causes the modal barrier to rebuild.
   ///
   /// It defaults to [Curves.ease].
   ///
@@ -1451,6 +1476,7 @@ abstract class ModalRoute<T> extends TransitionRoute<T> with LocalHistoryRoute<T
   @override
   void changedExternalState() {
     super.changedExternalState();
+    _modalBarrier.markNeedsBuild();
     if (_scopeKey.currentState != null)
       _scopeKey.currentState!._forceRebuildPage();
   }
@@ -1493,9 +1519,9 @@ abstract class ModalRoute<T> extends TransitionRoute<T> with LocalHistoryRoute<T
         barrierSemanticsDismissible: semanticsDismissible,
       );
     }
-    if (_filter != null) {
+    if (filter != null) {
       barrier = BackdropFilter(
-        filter: _filter!,
+        filter: filter!,
         child: barrier,
       );
     }
diff --git a/packages/flutter/test/widgets/overlay_test.dart b/packages/flutter/test/widgets/overlay_test.dart
index 50ebfde26c..bbbb9f0f7e 100644
--- a/packages/flutter/test/widgets/overlay_test.dart
+++ b/packages/flutter/test/widgets/overlay_test.dart
@@ -1039,7 +1039,7 @@ void main() {
     final dynamic renderObject = tester.renderObject(find.byType(Overlay));
     expect(renderObject.clipBehavior, equals(Clip.hardEdge));
 
-    for(final Clip clip in Clip.values) {
+    for (final Clip clip in Clip.values) {
       await tester.pumpWidget(
         Directionality(
           textDirection: TextDirection.ltr,