Music Cover

From the imprint created this shell is great and I really like them. What bothers me somewhat, but I would probably even have to think about it, that it discolors somewhat namely yellowish around the edges. Possession this envelope now only a few months. I must say, I'm wearing my phone usually in your pocket, but I wipe it but often times from. Here is the discoloration. Otherwise very cool cover. VII would be the solution to print the background in black and white in the font?