Well judging by this thread, yes i did play with that a lot, but, only cause Android is but ugly by default, most of them, so you practically have to change it to your liking, but only some parts of it/homescreen, the rest of the UI remains ugly.
It's a devils thing that, you never get sattisfied with how it looks, at least i don't, and you keep changing it indefinately.. it's good that everything looks and behaves beautifully from the box for a change.