Uniform

Beginning with its founding in 2181, the exploration and defense forces of the United Federation of Planets required a uniform to provide consistent identification of all forces. Despite this move being considered 'militaristic' by some elements of the Federation Council, Starfleet separated itself into two branches. For the next several hundred years, the Starfleet Naval Service handles the majority of space-based defense and research work, while the Starfleet Marine Corps carries on surface-based missions.

Coloration
In the service of a large organization like Starfleet, it is important to divide responsibility for the operations and maintenance of spacecraft, land bases, and permanent spaceborne installations. To this end, there are six divisions within Starfleet, each of which has a set of responsibilities. Cadets in the Academy take basic education in all six disciplines together with basic rigour and decorum for the first year, and thereafter are permitted to study any of the wide range of classes available, with their final discipline decided by the aggregate total of classes passed.

Features
PocketsAll Starfleet uniforms since 2181 have several expandable pockets; as of 2391 the uniform has one on each of the outer upper arms, 'slash' pockets at the hips, and one expandable each at the thighs. When not in use, the pockets are pulled completely flat and pressure-zipped to the rest of the uniform, 'disappearing' completely into the garment. Electromagnetic zippersWhile not capable of attracting first-stage magnets, the fields generated by $$\overset{2}{Nd}$$ (dineodymium) are strongly self-attractive. Beginning in 2298, dineodymium threads are woven into the edges of the garment's adhesive surfaces, and stick fast when pressed together even under heavy shear forces. The zipper is enabled or disabled by a finger run across the two surfaces as they are placed against each other. If the uniform is not powered, the surfaces remain adhered but will not reseal once separated. Programmable pigmentationStarting in 2298, Starfleet began use of programmable pigment rather than producing clothing in all divisional colours. While the uniform is powered (by a communicator badge, wrist tricorder or other affixed equipment), upon affixation of a user's communicator badge and double-tap the user is logged into the badge via genetic scan of deposited skin material. The uniform's pigment surfaces change to match the user's divisional colour. A uniform with no power from whatever source reverts to reflecting all wavelengths, appearing as white.

The Starfleet naval uniform features specialised mount points for a hand tricorder, small arms or power cells; the Marines uniform swaps the standard work boots for combat boots and includes mount points for a tactical harness which provides a personal shield generator and mount points for standard equipment, explosive packs, transponders for transport signals etc. Flag officers receive dress boots and extra power systems on the belt.

Development
The uniform used by Starfleet has changed over time, as in any quasi-military force.

2182-2194: Formation
Starfleet's uniform at the time of its formation in 2182 was heavily based on the jumpsuits worn by previous human space-faring organisations; it put a low priority on identifying specialisation, and use of mission patches was standard practice. It consisted of a blue jumpsuit with trim of divisional colour on the shoulders, and rank insignia were located on the right shoulder.

2195-2297: Romulan War and Klingon Cold War
When first contact with the Romulans resulted in open warfare, Starfleet adopted a new uniform designed to appear more militaristic as its responsibilities shift from scientific research to defence of the realm. The blue jumpsuit was replaced with a red tunic on a white undershirt with a band of divisional colour down the legs of the trousers; rank insignia were oriented vertically on a white bar on the right shoulder.

2298-present: An Exploratory Fleet
With the peace accords at Khitomer in 2297 ending decades of cold war with the Klingons, Starfleet returned to a more peaceful exploratory mission and altered its uniform accordingly. The new uniform placed the divisional colour across the shoulders on a black background with a grey-blue undershirt, with rank insignia on the right side of the neck. In addition, Starfleet began using a decorative dress uniform consisting of a long tunic in divisional colour with a black yoke and rank insignia located on the shoulder.

2367-present: Borg and Dominion invasions
Starting with the first hostile incursion of the Borg into Federation territory, Starfleet began use of a combat variant of the uniform first adopted in 2298, consisting of a grey padded yoke on a black background with a stripe of divisional colour around each arm and an undershirt in divisional colour.