Robert's link is, in fact, based on Itten.
No color like celphone color
More color-theory links
For a practitioner, the books by Josef Albers are excellent.
The Gabriel Bauret COLOR PHOTOGRAPHY is pretty darned swell, too
This page on color trends will give you some special insights on cultural application of color. Or make you throw up. Or both.
Perceptual shifts may also be medical, as in synaesthesia.
NLP practitioners have shown that they can pretty easily induce synaesthetic color experiences in most anyone, indicating that the experience is not actually rare at all -- only the recognition of it is.
As mentioned in this Science News article, researchers have found that color expectations can have direct effect on readability of (Chinese) text -- seeing the word "red" written in blue takes longer for the brain to process and understand.
"The psychology comes from the underpainting" is one of the strangest lines I've read in weeks.