<!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>