Felix Crux

Firefox's cross-platform nature means that it doesn't always fully integrate natively into your desktop. This was particularly apparent to me when using dark-coloured GTK themes under Ubuntu Linux. By default, Firefox looks something like this:

But, with a bit of tweaking to your userChrome.css file, which lives under ~/.mozilla/firefox/<random-looking-name>.default/chrome/, we can make it a bit nicer:

First, let's make the tabs a little more legible, and get rid of the gradients:

tab {
  background: rgb(50,50,50) !important;
  color: rgb(200,200,190) !important;
}

tab[selected="true"], #nav-bar {
  background: rgb(70,70,70) !important;
  color: rgb(160,200,200) !important;
}

#urlbar {
  color: rgb(200,200,200) !important;
}

We can also improve the appearance of the awesomebar, including the suggestions:

.ac-comment {
  font-size: 100%! important;
}

.ac-url-text {
  font-size: 100% !important;
  color: rgb(160,200,200) !important;
}