If you divide the solar spectrum roughly into half, you will have: the reds,
oranges, and yellows on one side and the purples, blues, and greens on the
other. The former being roughly the warm and the latter the cool colours.
Cool Colours are Calming. The blue side of the spectrum along with cool browns
and grays and the cool off whites possess all of the qualities of coolness in that
they are calming, focusing and soothing to our INTELLECT, which craves a
cooler atmosphere.