I got my iPhone 6 changed on Apple Store due to a loose home bottom. Apple sent me a new iPhone. I have noticed that the display colors are a bit more different from the first iPhone 6. Everything looks a bit brighter and the blue is a bit greyish. If compared my display to my brothers iPhone and the colors on his device are a bit more yellowish. If I turn the brightness fully up on both devices mine is a bit brighter? Is it normal that apple use different displays on iPhone 6? Anything to be concerned about?