My future plans for my playthrough will include color coded outfits for all my mages and priests. As a result I've been looking into what each magic school uses for a color. I find that there's a tad bit of confusion about the colors given to some of the different schools of magic. Some, like Destruction, Conjuration, Necromancy and to a lesser extent Restoration, are pretty much spoken for, but what about Alteration, Illusion and Alchemy? Beth didn't make things any easier by making the tomes for Alteration and Illusion the same color for Skyrim.

Destruction = Red

Conjuration = Purple

Necromancy = Black

Restoration = Yellow/White?

Illusion = ???

Alteration = ???

Alchemy = ???

Also, I was thinking about bringing Druids into it at some point. I'm not too sure how to even define their school of magic, or do they use a mix of Alchemy, Restoration, Alteration and Illusion?

Or is it all up to personal interpretation to a great extent? I've been on quite a few forums where they even disagree about Conjuration and Destruction! About the only magic school that seems to remain constant is Necromancy being black, the color of death.

These were the colors used in Morrowind and Oblivion:

Destruction - Red

Conjuration - Yellow

Alteration - Purple

Restoration - Blue

Illusion - Green

Mysticism - Pink

When I played Oblivion I never used magic at all. It was also quite some time ago so I don't remember a lot of it. But it is surprising the list you give for the colors, because in Skyrim Conjuration has a purple tome and Restoration has a yellow tome. Wonder what caused Beth to break continuity like that?

I don't think there ever was a continuity about colors of school