Apple has been remarkably inconsistent in the color temperatures of their displays. I measured the white point of the early LED backlit macbook pros around 8000K. The CCFL panels had a white point closer to 6500K. I don't typically say D65, because that's a color, not a temperature. The 27" cinema display that preceded the thunderbolt display was around 7000. Lower means more yellow, and comparing them side by side is meaningless. Whatever you're used to will look better. Now if you're away from it for a while and then sit down and it looks yellow, you might walk into the Apple Store and see how yours compares with the display models of the same generation. This means ignore anything that doesn't match your model unless you're willing to buy something else entirely.
but all Macs in pictures are set to d65! why one is white and one is yellowsh
D65 refers to an exact color, and not all Apple hardware has a native white point close to D65. Most of the recent stuff does.
ok, I understand. but how do I know which of the two display is calibrated correctly? (for me the white of my rMBP seems more "normal", while the display of my new tbMBP does not look white.
You can't really calibrate these things. I don't know why people keep suggesting it. It is very bad advice. Now there are displays that have some lower level controls, allowing for some amount of calibration. Even today they cost a lot of money, assuming you buy one that lives up to its claim.
Your display has a profile assigned to it by colorsync or whatever Apple uses these days. It indicates the characteristics of your display to the best of its knowledge and any secondary transformations it should perform in an attempt to match a particular target. Typically I would suggest that you leave this stuff alone. If it's genuinely much more yellow than others of the same model, then swap it with another. If the new displays just happen to be warmer, then this won't help. Profiling a display to something other than its native color temperature is really bad advice, and it needs to go away.