June 23, 2010 
SoSly 
A number of new iPhone 4 owners are reporting that their just delivered devices are suffering from a yellow discoloration on the retina display. Currently, there is no explanation for why this is happening and Apple Stores have no replacements available.
Threads have been started at MacRumors and the Apple Discussion Forums about the issue.
Hopefully this isn’t a widespread problem… For More Pics
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Well, a Rumor is just a Rumor, until proven otherwise (I’ve wanted to say that !)
ans those colors could be the known colors we see when we try to take a photo of a screen with an Aaaaaaah to average camera.
Yes you are correct but a few people have posted pics of their own. Whatever it is apple will replace them asap anyways
Apple Insider:
Apple is using a bonding agent called Organofunctional Silane Z-6011 to bond the layers of glass. Apparently, Apple (or more likely Foxconn) is shipping these products so quickly that the evaporation process is not complete. However, after one or two days of use, especially with the screen on, will complete the evaporation process and the yellow “blotches” will disappear.
How do I know? I was involved in pitching Z-6011 to Apple.