<!--
     Any copyright is dedicated to the Public Domain.
     http://creativecommons.org/publicdomain/zero/1.0/
-->
<html>
<style>
#b {
  width: 200px;
  height: 200px;
  background-color: rgb(0,255,0);
}
#c {
  z-index: 1;
  position: absolute;
  top:100px;
}
</style>
<div id="b">
<svg width="100" height="100" viewBox="0 0 100 100" >
  <rect style="fill:#00FF00;mix-blend-mode:difference;" width="100" height="100"/>
</svg>
<div id="c">
<svg width="100" height="100" viewBox="0 0 100 100" >
  <rect style="fill:#00FF00;mix-blend-mode:difference;" width="100" height="100"/>
</svg>
</div>
</div>
</html>