I just had my iPhone4S replaced at the AppleStore because of faulty mic/reciever operation that's plaguing other users. By the looks of it, its affecting some of you here.
Upon return from the store, I've noticed a yellow tint to my screen that as much as I can remember wasnt there with my previous phone. Perhaps its because I saw about it elsewhere in these forums, but its been bugging me since I've changed to the new phone.
Though I cant prove it, since i don't have my old 4S, I swear the colors are different.
Compared with my previous iPhone 4, which I still have in possestion, the screen is noticably yellow (warm).
As I work in advertising, and deal with a great amount of photography, it is a problem.
Hopefully, Apple will address the color issue in an upcoming software update.
I'm going to visit the Apple Store in a day or two to compare mine with what's on display. If there is a significant difference, I'm going to ask for swap.