| What is interesting is the cultural dynamic at work here.
These color assignments are largely cultural. In Japan, for instance, white, not black, is associated with death. People who spend a lot of time around nature are likely to associate green with life or plants rather than envy, greed, and jealousy. But overall the original color suggestions given above are true, for a Western (possibly only American) viewpoint.
Still, though, people will associate color with certain things -- Isaac Bonewits claims there is a universal spectrum with respect to magic rather than just black magic and white magic. I'd love to just type it in, but I don't want to risk a copyright problem and I don't understand it as well as other things to phrase it in my own words with my own experience -- find a copy of Real Magic. I will say, that he suggests that yellow is indeed associated with thought. | 
