I bought an iPhone 7+ and realized that the screen was kinda yellowish. I went to the Apple store to compare with other iPhone 7+ and their devices had really nice blueish ("normal") screen. I asked a guy who works there and he said it's completely normal and there's nothing I can do about it. Has this happened to anyone else..? I don't know why but I just hate yellow screen. Should I return it and get a new one, which may also have yellow screen?