Depends on the forum. I'm a moderator in most of the forums, but not all of them. In a specific forum, the moderator of that forum has green stars.
As for the rainbow and purple, those are both gay symbols.
Trust me. I lived in Sydney, which considers itself the international version of San Fransisco. Which means that it is really, REALLY gay.
Purple was the color of the roman emporers. It was the hardest of the colors to dye anything, and it was hard to maintain the color, so it was only used by the richest of the rich.
I don't know the history of the rainbow as a symbol, other than God would probably be a little peeved that people are using his promise that he wouldn't flood the earth again as a symbol for people who like it in the pooper.
-Kid Vid