"Psychologists believe color does more than impact our visual systems. For example, the same mechanisms which receive color input, also allow the pulses to reach the pituitary and pineal glands by way of the hypothalamus. The pituitary regulates certain hormones and other physiological processes. In fish, it is believed the pituitary may even regulate color. The pineal, interestingly, was thought by Decartes to contain the soul. It is believed generally that at least temporary responses affecting mood occur as a result of exposure to certain colors – red to stimulate, blue to calm, and so on." - AJ Kohn from Bookmarklet