Don't worry about it...it'll turn grey and white soon enough. 
* Close all Firefox windows, including the download manager window, themes window, and/or extensions window if they're open.
* Double-click My Computer, My Documents, etc. (Your choice.) The window that comes up is known as Windows Explorer.
* Copy the following, excluding the quotation marks: ''C:\Documents and Settings\username\Application Data\Mozilla\Firefox\Profiles\''. (Sidenote: I originally said ''local drive'' because although the local drive is ''C'' for most people, it's not for everyone.)
* Paste that into the address bar of Windows Explorer.
* Where is says ''user name'', change it to what ever the username is that you use to log onto Windows, then press enter.
* You should now see a folder that's named a series of random letters and numbers, followed by ''.default''. Double-click it to open it.
* There are four items you need to delete that are noted in my previous post. The part in quotation marks is the name of the item, and the part in parenthesies is the type of item. (If it's a folder or file, and what type.) Select each one at a time and press the delete key.
* Sidenote: What that does is delete any/all themes and extensions you had installed, as well as the files that stated they were installed. Default versions of these files should be created automatically when you launch Firefox.
* Launch Firefox.
* Verify that there are no themes or extensions installed by going tools->extensions and tools->themes.
* Redownload any extensions and themes you may want.
* Select the theme and click ''use theme.'' (It'll tell you it'll apply the theme the next time you restart Firefox.)
* Close all Firefox windows, then relaunch it. Your desired theme should be used and extensions should work properly.
Let me know how it goes.
John