Changing Desktop Interface Appearance

Ok, I have a bit of a silly question, but I'm curious myself. I have a co-worker who asked me today if she can change the desktop GUI color....she wants it to be pink :) Because she's done a lot of hard work for me lately, I thought I'd try to figure that out for her. I can't, so I'm thinking this isn't an option. If it is, I would like to award her with a pink ArcMap desktop. :)

Thanks,
Mike