They're all staff, so why the different coloured names?
Purple = Administrators; Administrators of the Site, wizards here to help with whatever you need!
Blue = Global Moderators; Here, there and everywhere! These guys are watching over the whole forum.
Green = Moderators; Here to help you out in the roleplay and social sections.
Pink = Techie Moderators; Here to help with all things technical regarding the site!
And here they are in name and title: