I use stylish to changes fonts and colors, here's my custom stylesheet

  * {
    color: #F3F1A1 !important;
    background-color: #000 !important;
  }
  body > center > table > tbody > tr:first-child * {
    background-color: #073642 !important;
  }
  body > center > table > tbody > tr:first-child * a:hover {
    background: #002b36 !important;
  }
  code, pre, input, textarea {
    background: #073642 !important;
  }
  a, .pagetop, .hnname a:visited, .rank, .athing {
    color: #b58900 !important;
  }
  .commtext {
    font-size: 125%;
  }
  .title {
    font-size: 112%;
  }
  .subtext {
      font-size:75%;
  }
  .subtext *, .sitebit, .sitestr, .subtext:nth-child(2) {
      color: #9e7800 !important;
  }
  a:visited, a:visited span {
      color: #717600 !important;
  }
  a:hover, a:hover span {
      background: #073642 !important;
  }

P.s. I am a slightly colorblind, please don't judge my colors palette