White Robes: Followers of Solinari. Good, beneficial magic. More into peace, don't hurt people (think of a Wiccan). Usually calmer, more in tune with nature.
Red Robes: Followers of Lunitari. Neutral magic. They don't lean towards good nor evil. During wars, they could fight with either side. Usually aren't out for power, or to further themselves, but have maybe slightly less morals than a White Robe.
Black Robes: Followers of Nuitari. Evil, self-furthering magic. They are out for themselves, and only themselves, and damn anyone who gets in their way. Usually don't care about anyone besides select family members and lovers, but for the most part they put getting more power above everyone. They have no scruples, and are willing to sacrifice anything and everything for their magic.