I just got a MacBook Air and the differences in color between it and my 2009 iMac are driving me crazy. I know there were certain iMac models from that period with yellow tinting issues, but I did the gray bar tests and that doesn't appear to be the issue. (No hardware issue suspected)
However, my iMac's tones are more yellow prone than the MacBook and I was wondering how to calibrate these two devices better for design work.