chromium/third_party/blink/web_tests/paint/resources/prefers-color-scheme.svg

<svg xmlns="http://www.w3.org/2000/svg" width='100px' height='100px'>
  <style>
    @media (prefers-color-scheme: dark) {
      rect {
        fill: green;
      }
    }
  </style>
  <rect fill='blue' width='100px' height='100px' />
</svg>