HorseC, I think you're thinking of the timestamp. Nick brackets must be done with a script afaik.
sjvirchow, If you want specific nicks or specific levels (regular user, voiced, halfop, op, etc) to be specific colors, you can change those in the Address Book (Alt-B > Nick Colors tab). Just add the nick or user level and set the color. If you want it random, then a script is necessary as mentioned.