Colors are a good place to start, but I really feel that chakras should be involved, naturally since ghey taiji is all about the chakras.
Instead of lower chakra, heart charkra, etc., they should have happeh names like: giddy chakra, tickle me chakra, giggle chakra, soap bubble chakra; and each one will be associated with a special chakra-enfused emoticon embroidered on the uniform as the student progresses upward along the ladder of energy refinement. Energy refinement being the goal of traditional ghey taiji as stated in the classics.
I could go on...