chromium/tools/perf/page_sets/tough_animation_cases/css_value_type_color.html

<!DOCTYPE html>
<meta name="viewport" content="width=device-width, user-scalable=no">
<link rel="stylesheet" type="text/css" href="resources/tablet.css">
<script src="resources/perf_test_helper.js"></script>
<script src="resources/css_value_type.js"></script>

<container id="container"></container>

<script>
perfTestCSSValue({
  property: 'background-color',
  from: 'rgba(0, 127, 255, 0.25)',
  to: 'rgba(255, 0, 127, 0.75)',
});
</script>