Looking to make Firefox a little darker, and perhaps even more mysterious? Look no further than the BlackFox theme for Firefox.
This is one of the few dark Firefox themes I could see myself using on a regular basis.
BlackFox is a very nice looking dark theme, with just a hint of red to help highlight your selected browser elements. The entire them has been designed to be focused, compact, and easy on the eyes.
The theme’s author also promises that it is compatible with a long list of popular extensions too.