all moderators will have green names,
administrators will have orange names and
site staff members will have dark brown names.
regular members will have black usernames
people on your friends list will have blue names. (in pms this will be black)
Gaia NPC accounts used by the staff will have red names.

They will aper in these colors in pms.

If you are not positive about it go to a post made by the person and see what color their name is.(above colors are the same for posts made in threads.)