I received my 13" retina macbook pro a few days ago and noticed that my menu bar up top is not grey all the way across. I turned the 'translucent menu bar' option off as well, just to make sure that my menu bar was a solid color. The middle 2 inches of the top of the screen is a cyan/blue tint that is best seen on the menu bar and address bar when in safari. It looks like all of the 13" rMBP's on display at the apple store had the same issue. The area affected is directly under the iSight camera. The 15" does not have this problem, only the 13". I purchased a second 13" to compare to my first one and they are both identical.