<!DOCTYPE html>
<link id="target" rel="stylesheet" href="data:text/css,">
<link rel="stylesheet" href="data:text/css,div { color: green }">
<link rel="stylesheet" href="data:text/css,">
<div>This should be green</div>
<script>
  onload = function() {
    var link = document.createElement("link");
    link.rel = "stylesheet";
    link.href = "data:text/css,div { color: red; }";
    link.title = "turnitred";
    var target = document.getElementById("target");
    target.parentNode.insertBefore(link, target);
  }
</script>