Well, mine is the casual XP gray, to save more memory...
What is your desktops main color?
My lovie "customized" mine. It was neon pink! Recently while doing a full reg scan and all kinds of cleaning my laptop, it changed back to plain ol' blue.
It has no main color, we have sort of a slideshow of pictures.
If I had permission to change it then I would probably have a mix of pink, blue, and black.