Doesn't have to be fancy, just something that works. Can save data in localStorage.
EDIT: I use Firefox.
https://github.com/lachlanmcdonald/hackernews-user-tags
(not thoroughly tested, so use at your own peril. HN runs in quirks mode and there is some nasty global namespaced JS. If you have any issues, do let me know)
// ==UserScript==
// @name HN brudgers
// @match https://news.ycombinator.com/*
// ==/UserScript==
for (let link of document.querySelectorAll('.hnuser')) {
if (link.innerText == 'brudgers' ) {
link.style.color = 'blue';
}
}
Worth noting that this type of script is fragile.Whenever HN changes it's HTML, CSS, Javascript, or code-generating code, it might stop working.