chromium/third_party/blink/web_tests/svg/custom/resources/rgb.svg

<svg id="svg-root" width="192" height="64" xmlns="http://www.w3.org/2000/svg">
  <g id="RGB">
    <rect id="R" x="0" y="0" width="64" height="64" fill="#c00"/>
    <rect id="G" x="64" y="0" width="64" height="64" fill="#090"/>
    <rect id="B" x="128" y="0" width="64" height="64" fill="#00f"/>
  </g>
</svg>