In the discussion today the “Five Colors” of Buddhism came up, and I mentioned the Tibetan Mandalas. If you look at this sand-painting mandala done at PSU last year, you’ll see the five colors:
PSU Mandala Day 4 - Whole, high view
Note the border around the edge: White, Yellow, Red, Green, Blue, over and over (clockwise). You can see the same colors in this hand drum. As near as I can tell, the five colors predates most of the explanations offered for their meanings — which is to say, there are lots of different explanations, because everyone seems to be making up new rationalizations for an old practice.