Users who want to change the Windows XP theme are left with two choices. They can go the official way and use the few official Windows XP themes that have been released by Microsoft or they can patch the uxtheme.dll file to be able to use user created XP themes. The first way is the easier one but limits the themes to a handful while the second requires patching a Windows system file but rewards the user with thousands of Windows XP themes.
The official XP themes have the advantage that they can be used right away. Royal Noir is a Windows XP theme that was discovered about two years ago. It comes as a blue and black theme with great contrasts.
Installation of Windows XP Royal Noir. Just download the Royale Noir package and unpack it on your computer. The contents have to be moved to windows\resources\themes\royal noir. A click on the luna.msstyles file should be located in the royal noir directory will activate the theme and bring the Display Properties to the front.
The default color scheme will be the blue one which will be shown as Royal in the Color Scheme menu. A click on the Color Scheme pulldown menu will display the second option entitled Royal Noir which will change the blue color to black upon selection.
http://www.ghacks.net/2008/09/09/royal-noir-theme-windows-xp/