JSFiddle - React, Tailwind, and code Playground

HTML

<div></div>
<style title="scrollbar">
    div {
        height: 1000px;
        width: 1000px;
        background-color: red;
    }
    ::-webkit-scrollbar {
        background-color: blue;
    }
</style>

JavaScript

for(var i = 0; i < document.styleSheets.length; i++) {
        var sheet = document.styleSheets[i];
        if(sheet.title == 'scrollbar') {
            for(var j = 0; j < sheet.rules.length; j++) {
                var rule = sheet.rules[j];
                if(rule.cssText.match("webkit-scrollbar")) {
                    rule.style.backgroundColor="yellow";
                }
            }
        }
    }