I'm too lazy to do a search, but I remember in cognitive psych in college they covered the human reaction to wall color for extended periods of time.
apparently in hospitals and most houses, they add a bit of blue to the white paint to make it more calming - what I don't get is they add red to the walls in prisons (pinkish) and that is also supposed to be calming and lower the liklihood of rage.
on the other hand, a turly red room was supposed to put you on the edge. and I don't think in a good way.
don't recall anything about yellow.
my girlfriend's dining room at her place is red and yellow, but not just regular red and yellow, and she lives in a tropical paradise, so the colors fit in better there than they would in say... boston.