I've searched everywhere and I can't find anything. It's most noticeable in bright light or sunlight but it definitely looks gray compared to the screen when it's locked. The back is probably the same but the dark screen really shows off how it is much different. I probably wouldn't have noticed except I was walking to my car with my 1st gen iPod Touch in my hand as well (I use it strictly for music) and the difference was night and day. The iPod was black as night and the iPhone 4 was grey. If they are all like this I'm fine with it. I am just inquiring. Maybe this has something to do with the white model delay in that when subjected to certain lighting it messes the "whiteness" all up and makes it look bad.