RandomLetters

Hi, I've been wondering about this for awhile. What I'm referring to are the blue menus that pop up when you click "Log Off" or "Turn Off Computer" in the start menu. I've been trying to get rid of all the blueness that Windows gives and I've already done so with my login however, I haven't been able to find where the images are located which make up said menu designs. So my question would be would anyone happen to know which file those images are located in? I'm using Windows XP home edition if it helps, thanks.