I've thought about and I think it'll be better to say they don't go with uniforms. Members of the New Guard are able to work with the organization for a suit that either complements their power or just for aesthetic purposes. They can just wear their own personal clothing as well.Here’s a question.
Does the New Guard have Uniforms? Will we as student have special Uniform Super Suits?
They do need some kind of way to indicate who they are with so each member gets a bad, while student trainees get temporary badges while on missions.