Very polished work amigo! I look forward to seeing them all. It's weird to see this as I was considering creating a colour coded batch of magic-users today, but I think I'll let you complete yours!
I was thinking:
Black - Corruption, Transformation, Change, Death, Alchemy : At their best they'd be flamboyant artists that alter themselves, at their worse twisted body sculptors that kidnap "subjects".
Yellow - Earth, Metal, Combat, Wealth, Stability, Order : I picture this as the school of noblemen, unmovable traditionalists, think the Great Wall of China built by the Emperor with his mind!
Blue - Water, Darkness [of the sea depths], Thought, Secrets, Stealth : Fluid ninjas that are always one step ahead and blackmail and kill their way to the top, perhaps control ice too, energy takers rather than all fizz-bang light-show about magic.
Red - Fire, Trickery, Illusion, Presence, Chance : Taking cues from Loki Liesmith and Prometheus, they'd be vagabond trickster-teachers, gamblers and fools that like to talk their way out of things, but can unleash fiery Hell if needed.
Orange - Air, Storm, Healing [breath of life as it were], Freedom [of movement], Fate : Peaceful monks for the most part, but only because no one wants to fight with a hurricane, lightening storm harnessing oracle of destiny!
Purple - Commandment, Summoning, Poison, Misdirection, Madness : Good old fashioned occultists that have seen too much, but most don't realise they're over the edge, when they summon things they'd crawl out of their mouths, all tentacles and spider-legs!
Green - Nature, Growth, Strength, [mastery of] Beasts, Emotion : Druids for the most part, with a little bit of stat boosts thrown in, more predators than tree huggers I imagine, I picture them covered in tattoos and piercings, little clothing or armour.
White - Light, Clarity [see magic, see invisible], Meditation [astral projection], Speed, [classical] Necromancy : Just as holy as most white magic users, these guys would be more like shaman of bokors, defenders of both the material and spirit world, they'd be able to talk to ghosts.
Grey - Utility [mage hand, magical mansion], Protection, Banishment, Purification, Dispelling : Witch hunting witches in Puritan get up, they would also have a number of simple, quick spells to get them through the day.
Thats... a lot of writing, sorry about that.