Mixing pigments (ink or paint) can be done in CMYK because it is a subtractive process. It would have been realistic and something that anyone who has played with finger paints or crayons has experienced. (Although I agree that it's not very relevant to the end result, it would have been nice to see it in the discussion.)
Geez, I feel stupid about that comment now. Was too much in the "monitors are RGB, CYMK is only for print" but of course, when mixing colors it might be good indeed.
