chromium/third_party/blink/web_tests/accessibility/resources/animation-green-red.svg

<svg xmlns='http://www.w3.org/2000/svg'>
  <rect width='100' height='100' fill='green' stroke-width='0'>
    <animate attributeName="fill" values='green;red' dur='1ms' fill='freeze'/>
  </rect>
</svg>