<!DOCTYPE html>
<svg>
  <clipPath id="c1">
    <rect width="100" height="100"/>
  </clipPath>
  <pattern id="p1" width="1" height="1">
    <rect width="100" height="100" fill="green"/>
  </pattern>
  <rect width="100" height="100" fill="url(#p1)" clip-path="url(#c1)"/>
</svg>