Proper light/dark colors, and test that text is not color of background (#67679)

packages/flutter/lib/src/material/search.dart

@@ -199,7 +199,9 @@ abstract class SearchDelegate<T> {
     final ThemeData theme = Theme.of(context)!;
     assert(theme != null);
     return theme.copyWith(
-      primaryColor: Colors.white,
+      primaryColor: theme.brightness == Brightness.dark
+          ? theme.primaryColor
+          : Colors.white,
       primaryIconTheme: theme.primaryIconTheme.copyWith(color: Colors.grey),
       primaryColorBrightness: Brightness.light,
       primaryTextTheme: theme.textTheme,

packages/flutter/test/material/search_test.dart

@@ -691,6 +691,56 @@ void main() {
       semantics.dispose();
     }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
   });
+
+  // Regression test for: https://github.com/flutter/flutter/issues/66781
+  testWidgets('text in search bar contrasts background (light mode)', (WidgetTester tester) async {
+      final ThemeData themeData = ThemeData.light();
+      final _TestSearchDelegate delegate = _TestSearchDelegate(
+        defaultAppBarTheme: true,
+      );
+      const String query = 'search query';
+      await tester.pumpWidget(TestHomePage(
+        delegate: delegate,
+        passInInitialQuery: true,
+        initialQuery: query,
+        themeData: themeData,
+      ));
+
+      await tester.tap(find.byTooltip('Search'));
+      await tester.pumpAndSettle();
+
+      final AppBar appBar = tester.widget<AppBar>(find.byType(AppBar));
+      expect(appBar.backgroundColor, Colors.white);
+
+      final TextField textField = tester.widget<TextField>(find.byType(TextField));
+      expect(textField.style!.color, themeData.textTheme.bodyText1!.color);
+      expect(textField.style!.color, isNot(equals(Colors.white)));
+  });
+
+  // Regression test for: https://github.com/flutter/flutter/issues/66781
+  testWidgets('text in search bar contrasts background (dark mode)', (WidgetTester tester) async {
+      final ThemeData themeData = ThemeData.dark();
+      final _TestSearchDelegate delegate = _TestSearchDelegate(
+        defaultAppBarTheme: true,
+      );
+      const String query = 'search query';
+      await tester.pumpWidget(TestHomePage(
+        delegate: delegate,
+        passInInitialQuery: true,
+        initialQuery: query,
+        themeData: themeData,
+      ));
+
+      await tester.tap(find.byTooltip('Search'));
+      await tester.pumpAndSettle();
+
+      final AppBar appBar = tester.widget<AppBar>(find.byType(AppBar));
+      expect(appBar.backgroundColor, themeData.primaryColor);
+
+      final TextField textField = tester.widget<TextField>(find.byType(TextField));
+      expect(textField.style!.color, themeData.textTheme.bodyText1!.color);
+      expect(textField.style!.color, isNot(equals(themeData.primaryColor)));
+  });
 }
 
 class TestHomePage extends StatelessWidget {
@@ -700,16 +750,19 @@ class TestHomePage extends StatelessWidget {
     required this.delegate,
     this.passInInitialQuery = false,
     this.initialQuery,
+    this.themeData,
   }) : super(key: key);
 
   final List<String?>? results;
   final SearchDelegate<String> delegate;
   final bool passInInitialQuery;
+  final ThemeData? themeData;
   final String? initialQuery;
 
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
+      theme: themeData,
       home: Builder(builder: (BuildContext context) {
         return Scaffold(
           appBar: AppBar(
@@ -749,11 +802,13 @@ class _TestSearchDelegate extends SearchDelegate<String> {
     this.suggestions = 'Suggestions',
     this.result = 'Result',
     this.actions = const <Widget>[],
+    this.defaultAppBarTheme = false,
     TextStyle? searchFieldStyle,
     String? searchHint,
     TextInputAction textInputAction = TextInputAction.search,
   }) : super(searchFieldLabel: searchHint, textInputAction: textInputAction, searchFieldStyle: searchFieldStyle);
 
+  final bool defaultAppBarTheme;
   final String suggestions;
   final String result;
   final List<Widget> actions;
@@ -761,6 +816,9 @@ class _TestSearchDelegate extends SearchDelegate<String> {
 
   @override
   ThemeData appBarTheme(BuildContext context) {
+    if (defaultAppBarTheme) {
+      return super.appBarTheme(context);
+    }
     final ThemeData theme = Theme.of(context)!;
     return theme.copyWith(
       inputDecorationTheme: InputDecorationTheme(hintStyle: TextStyle(color: hintTextColor)),