mozilla-release/layout/reftests/css-blending/background-blending-image-color-gif.html

<!DOCTYPE HTML>
<html>
<style>
.reftest {
  width: 100px;
  height: 100px;
  background-size: 100px 100px, 100px 100px;
  background-repeat: no-repeat;
}

.blend {
  background-color: rgb(255,255,0);
  background-blend-mode: difference;
}

.gif {
  background-image: url('as-image/red_green.gif');
}

</style>

<body>
	<div class="reftest blend gif"></div>
</body>
</html>