My iMac had the slightest bit of yellow tinge when I got it early February. I put it on file with apple and they said I could replace it if I wanted, but it was really minor and I figured I would wait and see how it all panned out, because at the time people were getting replacement after replacement still yellow. I did not really test or look closely before the recent firmware update, but now my screen looks perfect, and I cannot tell if I am just used to it, or did the firmware really fix. The light start screen looks good too. Is it me or did the latest firmware really fix the yellow? Has there been any discussion on this?