Not sure if it's an optical illusion, but is the iPhone 6 naturally warmer than, say, the iPhone 4? As that had a cool temperature look to it whereas the 6 is warm. It's like there's a very slight yellow tint when I look at white and I only notice it in a lowly lit room whereas during the day it's not too bad. It's kind of annoying me though.. Is it worth going to an Apple Store and asking for a replacement, but asking to compare it first with the replacement phone? I don't want one that's worse off.