iPhone 4s screen seems sepia/yellowish compared to 4

Ive recently got the iphone 4s and havent used it whilst i am wating for my number to be swapped from my iPhone 4. Ive just looked at them side by side and the screen on the 4s seems yellow like a sepia effect? i googled it and didnt get any clear answers, should i take it back or can i fix it myself?

If it's a new iPhone 4S, then you should definitely take it back if you think there is something that's off. Do not attempt to repair it..

I meant any fixes or settings that might help. Ive had another look and one suggestion was the glue was not set so to leave it on full brightness and with auto lock off for 1/2 hour. Thats what i am doing now so will see what happens. I am going into the apple store this weekend so i will bring it up with them if i still have the problem. I just wanted to see how common it was, although if i didnt hold my iPhone 4 up to it i dont think i would have realised the extent of the colour difference.