Personally, I am not much of a fan of that purple cloak. It's not too different from the blue you used, and so it clashes with the blue instead of complimenting it (I'm sure someone more knowledgeable in colour theory could give a more detailed explaination

).
Red cloaks work fine, good all around colour I find. White works well for lighter shades of blue, though I know a lot of people prefer not painting white unless they have to. Yellow cloaks will look too garish, I wouldn't go for that anyway. Just my thoughts there