anchor.diff:          within<Color>(distance: 8, from: const Color(0xff0000ff)));
     });
   
  -  test('PaletteGenerator works on 1-pixel high red image', () async {
  -    final ImageProvider image = await loadImage('wide_red.png');
  +  testWidgets('PaletteGenerator works on 1-pixel high red image',
  +      (WidgetTester tester) async {
  +    final ImageProvider image = testImages['wide_red'];
       final PaletteGenerator palette =
           await PaletteGenerator.fromImageProvider(image);
       expect(palette.paletteColors.length, equals(1));
  
positive.code:     expect(palette.paletteColors.length, equals(15));
    });
  
    test('PaletteGenerator Filters work', () async {
      final ImageProvider image = await loadImage('landscape.png');
      // First, test that supplying the default filter is the same as not supplying one.
      List<PaletteFilter> filters = <PaletteFilter>[
        avoidRedBlackWhitePaletteFilter
  
negative.code:         within<Color>(distance: 8, from: const Color(0xffff0000)));
    });
  
    testWidgets('PaletteGenerator finds dominant color and text colors',
        (WidgetTester tester) async {
      final ImageProvider image = testImages['dominant'];
      final PaletteGenerator palette =
          await PaletteGenerator.fromImageProvider(image);
      expect(palette.paletteColors.length, equals(3));
  