GreaseMonkey script to undo HN's contrast effects

hacker-news-contrast-fix.js

// ==UserScript==
// @name        HN font-color
// @namespace   hackerNewsFix
// @include     https://news.ycombinator.com
// @include     https://news.ycombinator.com/*
// @version     1
// @grant       none
// ==/UserScript==

var comments = Array.from(document.querySelectorAll('span[class^=c]:not(.comhead)'));
var rgb = /rgba?\((\d+),\s*(\d+),\s*(\d+)\)/;
var black = '#000';

comments.forEach(function (el) {
  var className = el.classList[0];
  var styles = window.getComputedStyle(el);
  var color = styles.color;
  var hexColor = rgbToHex(color);
  el.style.color = black;
  
  if (hexColor === black) return;

  var ageEl = el.parentElement.parentElement.querySelectorAll('.age')[0];
  var div = document.createElement('span');
  div.textContent = ' | ' + hexColor + ' | ';
  div.title = 'color class is ' + className;
  ageEl.before(div);
});

function rgbToHex (color) {
  var match = rgb.exec(color);
  if (!match || match.length < 4) return null;
  
  return '#' + match.slice(1).map(function (n) {
    if (n.length === 1) {
      n = '0' + n; 
    }
    
    n = parseInt(n);
    
    return n.toString(16);
  })
  .join('');
}