I also like his clothing; it shows how he doesn't go with the flow, wearing his own style. He's not like normal wizards, wearing cloaks and robes and acting "wizardly". He's showing everyne hat you don't have to be like everyone else. He loves to clash with thers, so why not wear clashing clothes? It goes back to his childhood I think he wasn't like the others, and had no one to really show him what was normal.