September 3, 2009 - 9:58 pm
A new Firefox theme featuring several Japanese cuteness powerhouse, Sanrio’s characters are now available at Mozilla Add-ons (experimental), courtesy of Erica Morgan.
So if you’ve been waiting to see Hello Kitty, Chococat, and other cuties, the wait is over! Get Sanrio.
August 10, 2009 - 8:43 pm
Here are a couple of well done themes for you to dress up your Firefox:
GoGreen to show how green you are: grass, corn, and recycling all in a single theme. Authored by Zamaan. Available at Mozilla Add-on.

July 5, 2009 - 11:50 pm
Rein, by Naoto Kusumi, is another clean, simple Firefox theme for those who appreciate invisible user interfaces while in use, and beautiful design when not.
The theme covers mostly everything: all built-in toolbar icons, sidebars, Add-ons Manager, Library, Options, Download Manager, all with a wink to good old Macintosh look. My only complain is that the buttonization of most icons in the managers results in some too small icons to be recognizable at a glance as they should be.
June 24, 2009 - 3:45 pm
Here’s FoxWorld, a modern, elegant Firefox theme by akgo, for those who prefer modern and elegant. Some of the secondary icons still missing, but a very nice approach indeed.

Available at the equally cool and revamped Mozilla Add-ons.
January 8, 2009 - 1:25 pm

Here’s another clean, elegant theme for Firefox 3, courtesy of Daum, a popular Sourth Korean Internet portal.
Developed by Channy Yun, Daum Blue gives Firefox a very calm and sophisticated look that resembles Chrome at some times with its large simple toolbar icons.
Icons in the Options window are also simplified, and you can opt for eqully appealing small toolbar icons.
Daum Blue is still marked as experimental on Mozilla Add-ons, so you will need an account to install it. Marked as Windows only.
January 5, 2009 - 10:09 am

Just in case one of your 2009’s resolutions is to get a new Firefox theme, here’s a suggestion: SKY. Created by Andrew Shay, it gives your web browsing a fresh, glassy look you may enjoy.
A plus! version is already in the works (for 3.1 betas only at this time) that adds a glossy toolbar background.
You can get SKY from Mozilla Add-ons.
December 4, 2008 - 9:11 pm
“It’s a-me! Mario!”, right here, in your back button.
Mushroom Kingdom, by Matt Coxwell, brings the joyful colors of Mario’s video game adventures to your favorite browser.

The customization is limited to the main window and the toolbar background starts tiling just above 1000 pixels wide, but who cares? Mario and Luigi go to sleep if there’s nowhere to go back or forward!
This is the best to happen to Mario since Super Mario Galaxy. Or maybe Kart Wii.
Anyway I suggest all Mario fans unite and push Matt to theme uninterruptedly until his work is complete.
Available at Mozilla Add-ons with account required at this time.
Via Firefox Facts.
November 30, 2008 - 5:21 pm
For the South Hemisphere and tropical countries it is not even cold, so white Christmas happens only on TV, movies and books…
… and Firefox. Here are three beautiful themes to make it snow on your desktop.
Xmas, by Matt Coxwell, my current favorite. It is an experimental theme so you will need a Mozilla Add-ons account to get the cute snowy roofs.

Tinseltown, another classic theme by Twister Mc.

Winter Holiday Christmas, developed by Brand Thunder, is technically an extension that includes a useless toolbar with links to Amazon, a few Last.fm stations, and evite. At least you can hide the toolbar and keep the well done theme.

Enjoy!
November 7, 2008 - 11:15 pm
Firefox 3 introduced tighter OS integrating across all platforms, and even different Strata (Windows theme) flavors for Windows XP and Vista. However the result was not optimal and there is room to make Firefox feel more native.

July 7, 2008 - 9:44 pm
As you may know, Firefox 3 introduces three different themes for all the officially supported operating systems: Firelight on Mac OS X, Tango on Linux, and Strata on Windows, which even comes in XP and Vista variations to better blend with Luna and Aero respectively.
If you are feeling envious of what the other platform or style got or just want to try a different look and have a couple of minutes to spare, you may want to give these themes a try.