On a tri or quad Cree mod, it is very easy to mask all LEDs except one, and then rotate your mask to compare tints.
I've just tried on a quad P4-WC and YES the tint is very different from an emitter to another. All four Leds were taken out of the same reel :huh:
Two are pretty snow white, one is more yellow and one is more blue. Doesn't really matter, since they are working together... and the "average" when using all four normally is a perfect and nice white tint so I guess I can't complain.
But thanks for pointing this out, I have totally discovered this today. That said, by doind what I just said you switch from an emitter to another very quickly, which makes any difference in tint look dramatic. If I had to test these leds separately, I can't garantee I would have seen a clear difference.