The theme, 8 Ultimo, is a smooth and dark theme for Firefox. If the default tones of your web browser have got you a little down, you might give this sleek theme a shot.
Here is a little more about the theme from the developers:
“8 Ultimo” is a theme that has been created to transform the look of Firefox (version 4 and higher) for Windows users. It has been specially designed for Seven, but rendering is relatively accurate on XP and Linux (I can t test it on MAC, but for those who would like to try it anyway on that platform, you can force download and once the package downloaded on your computer, you can install it manually by dragging it into the add-on manager). It contains no added functionalities, it’s simply a full Firefox’s GUI customization.
Dark themes for Firefox (that actually look good) used to be a dime a dozen. These days though, it is very hard to find a nice looking dark Firefox theme. If needed, you can also find some great wallpapers that go with this Firefox skin here.
You can download the 8 Ultimo theme from the Firefox Add-ons website.