If you're the type to prefer a seriously minimal desktop—so much so that you choose a solid-color desktop over setting a custom wallpaper—you may be wondering why-oh-why Windows 7 takes so long to boot your machine.
Turns out a bug in Win7 and Windows Server 2008 R2 causes a 30-second delay at login. Microsoft discusses the problem, potential solutions, and offers a hotfix here (
http://support.microsoft.com/kb/977346), though you could also just set a desktop wallpaper of your own.
We've got tons of great suggestions for you, or if you're really set on the whole solid-color thing, you could just create a single-color image with your image editor of choice and tile it as your wallpaper (
http://lifehacker.com/tag/wallpapers/).