Starfleet uniform (2373-2386)

The Starfleet uniform  was redesigned and introduced in 2373, with the previous version slowly phased out over a period of years.

Duty uniform
The new two-piece uniform was fashioned from a thicker, heavier quality fabric and, like the previous version's jumpsuit variant, was almost all-black. The jacket had quilted heather-gray shoulders with the wearer's division or department indicated by a coloured sleeve stripe near the cuff. The under-shirt was also coloured to denote the division, the collar of which protruded from the neck of the jacket and held the rank insignia. ( et al, )

Variations
Variations of this uniform existed, including a formal double-breasted tunic-style jacket with a division-coloured lining. This jacket could be worn with fitted trousers and calf-length boots, and was in service some time after 2379. (Starfleet Academy SCISEC Briefs episodes)

Flag officer uniform
The flag officer's version of this uniform style was introduced no later than 2374. The tunic-style jacket ended at the hips and could be secured with a belt buckle around the waist. It was decorated with gold piping around the collar and along the front fastening seams. The division-coloured stripe around the cuff was wider than on the standard duty uniform, with a further rank insignia pin attached on each stripe. 

Dress uniform
Introduced no later than 2375, the dress uniform was a complete departure from previous styles, with a white waist-length jacket and gold braid trim.