Since I bought my retina Macbook pro back in January I've gotten a lot of troubles with it. Two broken logic boards, two LG screens with image retention, GPU throttling issues.. etc, etc, etc.. But finally after a lot of time spent in the technical service, I have a Samsung screen and a good logic board... but wait a minute, it looks so yellowish!! I think that the problem is that when they exchanged the LG screen for the Samsung screen, OSX remained calibrated for the original LG screen as they didn't change the hard drive. I really don't want to go to a Genius bar again in my life, so I tried to make the trick with OSX's integrated Image Calibration tool. Just go to / System Preferences / Displays / Color / Calibrate / Click Expert Mode and continue / Go through all steps / Set gamma 2,2 / And at the end just set the white point to a level that a white safari's background looks white. My white point is set to 8000 ºK, and now it looks just OK. Which is yours?