I think it would be cool for the wing mounts to be school specific when bought from the crown shop. Sorta like the level 55 wands in Celestia when they are acquired after the quest is complete. Some Ideas are as follows:
Fire School: Wings of fire..like the phoenix spell Ice School: Wings covered in ice and snow Storm School: Wings made of electricity Myth School: Not quite sure Death School: Skeletal dragon/bat wings Life School; Wings made of giant leaves Balance School: Not quite sure
I suggest this option because a lot of our clothing in the game are brightly colored or very unique and i think only having black or white wings don't do some our our awesome outfits any justice.