Eric,
Thank you for your reply. So does this means the problem is in my app, or is it in AdMob portal and would be fixed soon? I don't think changing the color from my app would be a good solution. I need to try several colors, I don't have something specific in my mind now. Code-based solution won't be a flexible one (specially that we wait for 10 days or so for Apple to accept new updates).
Thanks,
Osama