There are these copper-red areas on the back of my evo both on the battery cover and around it. I dismissed it at first as something I may have stained it with but then more areas started to appear. And then I thought about phone is in a case at ALL TIMES so I was wondering what this was. After googling this issue, I am starting to think that it is the red color that underneath the black 'paint' for lack of a better word. But why is this happening?...I have not been rubbing the back of the phone against anything as it is always in a case.

Does anyone have any idea what's going on and if I can put something on it to clean it somehow? I read on another forum that I could use rubbing alcohol....what say you?