Do people really upgrade for a chat color? I would have thought /fly and awesome spawners would be far better reasons.
I think there are too many colors in use already, and it makes it too easy to miss important things. If you make Ults turquoise, they look too much like /jobs messages and pm's, which means when Global is busy and people are working their jobs, they won't see pm's.
Less use of text colors means the colors that are used are more meaningful and attention-grabbing, which is the point of using different colors in the first place. I'd like to see all chat but staff in white. Different colors can still be used on the donor title and the usernames, if everything else is white.
