chromium/third_party/blink/web_tests/external/wpt/css/css-color/hwb-003-ref.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>CSS Color 4: CSS Color 4: hwb</title>
<style>
    .test { background-color: rgb(50% 50% 50%); width: 12em; height: 12em; } /* hwb(0 100% 100%) converted to sRGB */
</style>
<body>
    <p>Test passes if you see a single square, and not two rectangles of different colors.</p>
    <div class="test"></div>
</body>