I'm fairly certain they are white as well. Apple does not disclose this info and I don't think the displays are expensive enough to be RGB (even the retina). They are also only 24-bit color. RGB LED displays seem to be geared towards high-end professional use and cost several thousand dollars. (plenty of pro graphics people use Apple displays)
I have a Macbook Air, Macbook Pro w/Retina and a Thunderbolt Display; I calibrate them all with i1profiler and things look great calibrated as white LED. I also think they do well with a custom contrast ratio of 1000:1, but I like to have a few profiles around for switching between high and normal contrast depending on what I'm up to.
Thanks guys for confirming that it's "White LED".
I use i1Profiler too and have always wondered, aside from setting contrast ratio to "native", what brightness setting should I set to using "fn+F1/F2" for the calibration?
I don't want to set a level too low that makes the screen hard to see during the day or setting a level too high for accurate calibration. Thoughts?