[material_ui] Respect ColorScheme.scrim in Drawer, ModalBottomSheet, and Dialog barriers

packages/material_ui/lib/src/bottom_sheet.dart

@@ -1342,7 +1342,10 @@ Future<T?> showModalBottomSheet<T>({
       clipBehavior: clipBehavior,
       constraints: constraints,
       isDismissible: isDismissible,
-      modalBarrierColor: barrierColor ?? Theme.of(context).bottomSheetTheme.modalBarrierColor,
+      modalBarrierColor:
+          barrierColor ??
+          Theme.of(context).bottomSheetTheme.modalBarrierColor ??
+          Theme.of(context).colorScheme.scrim.withValues(alpha: Colors.black54.a),
       enableDrag: enableDrag,
       showDragHandle: showDragHandle,
       settings: routeSettings,

packages/material_ui/lib/src/dialog.dart

@@ -1706,7 +1706,7 @@ Future<T?> showDialog<T>({
             barrierColor ??
             DialogTheme.of(context).barrierColor ??
             Theme.of(context).dialogTheme.barrierColor ??
-            Colors.black54,
+            Theme.of(context).colorScheme.scrim.withValues(alpha: Colors.black54.a),
         barrierDismissible: barrierDismissible,
         barrierLabel: barrierLabel,
         useSafeArea: useSafeArea,

packages/material_ui/lib/src/drawer.dart

@@ -713,7 +713,9 @@ class DrawerControllerState extends State<DrawerController> with SingleTickerPro
       };
 
       final Color scrimColor =
-          widget.scrimColor ?? DrawerTheme.of(context).scrimColor ?? Colors.black54;
+          widget.scrimColor ??
+          DrawerTheme.of(context).scrimColor ??
+          Theme.of(context).colorScheme.scrim.withValues(alpha: Colors.black54.a);
       final Color effectiveScrimColor = scrimColor.withValues(
         alpha: scrimColor.a * _controller.value,
       );

packages/material_ui/pending_changelogs/change_2026_08_15_scrim_color.yaml

@@ -0,0 +1,3 @@
+changelog: |
+  - Fixes `Drawer`, `showModalBottomSheet`, and `showDialog` ignoring a custom `ColorScheme.scrim` and always using `Colors.black54` for their scrim/barrier.
+version: patch

packages/material_ui/test/bottom_sheet_test.dart

@@ -1018,6 +1018,37 @@ void main() {
     expect(modalBarrier.color, barrierColor);
   });
 
+  testWidgets('Modal barrier color respects ColorScheme.scrim when not overridden', (
+    WidgetTester tester,
+  ) async {
+    final scaffoldKey = GlobalKey<ScaffoldState>();
+
+    await tester.pumpWidget(
+      MaterialApp(
+        theme: ThemeData(colorScheme: const ColorScheme.light(scrim: Colors.red)),
+        home: Scaffold(
+          key: scaffoldKey,
+          body: const Center(child: Text('body')),
+        ),
+      ),
+    );
+
+    unawaited(
+      showModalBottomSheet<void>(
+        context: scaffoldKey.currentContext!,
+        builder: (BuildContext context) {
+          return const Text('BottomSheet');
+        },
+      ),
+    );
+
+    await tester.pump();
+    await tester.pump(const Duration(seconds: 1));
+
+    final ModalBarrier modalBarrier = tester.widget(find.byType(ModalBarrier).last);
+    expect(modalBarrier.color, isSameColorAs(Colors.red.withValues(alpha: Colors.black54.a)));
+  });
+
   testWidgets('Material3 - BottomSheet uses fallback values', (WidgetTester tester) async {
     const Color surfaceColor = Colors.pink;
     const Color surfaceTintColor = Colors.blue;

packages/material_ui/test/dialog_test.dart

@@ -603,6 +603,32 @@ void main() {
     expect(tester.widget<ModalBarrier>(find.byType(ModalBarrier).last).color, Colors.pink);
   });
 
+  testWidgets('Barrier color respects ColorScheme.scrim when not overridden', (
+    WidgetTester tester,
+  ) async {
+    await tester.pumpWidget(
+      MaterialApp(
+        theme: ThemeData(colorScheme: const ColorScheme.light(scrim: Colors.red)),
+        home: const Center(child: Text('Test')),
+      ),
+    );
+    final BuildContext context = tester.element(find.text('Test'));
+
+    unawaited(
+      showDialog<void>(
+        context: context,
+        builder: (BuildContext context) {
+          return const Text('Dialog');
+        },
+      ),
+    );
+    await tester.pumpAndSettle();
+    expect(
+      tester.widget<ModalBarrier>(find.byType(ModalBarrier).last).color,
+      isSameColorAs(Colors.red.withValues(alpha: Colors.black54.a)),
+    );
+  });
+
   testWidgets('Dialog hides underlying semantics tree', (WidgetTester tester) async {
     final semantics = SemanticsTester(tester);
     const buttonText = 'A button covered by dialog overlay';

packages/material_ui/test/drawer_test.dart

@@ -209,6 +209,36 @@ void main() {
     await checkScrim(const Color(0xFF323232));
   });
 
+  testWidgets('Drawer scrim respects ColorScheme.scrim when not overridden', (
+    WidgetTester tester,
+  ) async {
+    Widget getScrim() {
+      return tester
+          .widget<Semantics>(
+            find.descendant(
+              of: find.byType(DrawerController),
+              matching: find.byWidgetPredicate((Widget widget) {
+                return widget is Semantics && widget.properties.label == 'Dismiss';
+              }),
+            ),
+          )
+          .child!;
+    }
+
+    final scaffoldKey = GlobalKey<ScaffoldState>();
+    await tester.pumpWidget(
+      MaterialApp(
+        theme: ThemeData(colorScheme: const ColorScheme.light(scrim: Colors.red)),
+        home: Scaffold(key: scaffoldKey, drawer: const Drawer()),
+      ),
+    );
+
+    scaffoldKey.currentState!.openDrawer();
+    await tester.pumpAndSettle();
+    final scrim = getScrim() as ColoredBox;
+    expect(scrim.color, isSameColorAs(Colors.red.withValues(alpha: Colors.black54.a)));
+  });
+
   testWidgets('Open/close drawers by flinging', (WidgetTester tester) async {
     await tester.pumpWidget(
       const MaterialApp(