Shipsuits are worn, carried, or kept close at hand when on board ship or minor space station. Dress uniforms, worn on planets (Class M, of course), habitats, and larger stations, are a bit different.
Ex Corps shipsuits have a base color of the member's department. Department chief shipsuit are reflective to symbolize that the department is the crew, not the chief.
Officer uniforms have sleeve and leg colors indicating rank. Crewmember, Crewleader, and Teamleader uniforms have the collar and legs colored, with arms matching the department.
Line Admirals and Admiral of the Corps wear a solid, reflective, department color.
Crewmember Recruits, not yet belonging to any department and having no rank wear a flat black shipsuit. Hence the slang term, "black sleeves."
Civilian specialists on board ship can wear anything they like, often indicating social standing, as long as it includes department and pay grade colors while on duty.
There is no regulation hair cut. Members may style it as they like, provided it is short enough to not cause trouble with a shipsuit hood deployed. However a ship's officers usually will wear the same style as set by the captain, tinted to match rank. Officers on station or habitat assignments, and general crew are under no expectations of hair style conformity, and on habitats, even wear it long (or wigs).
Note: The dress uniforms look suspiciously like those worn by Japanese high schoolers, but with no gender restrictions on who wears pants or skirts.