Starfleet uniform (alternate reality)
At some point after the destruction of the  in the alternate reality, Starfleet introduced a new Starfleet uniform design that implemented a red/gold/blue color scheme: gold being for command division, red for operations, and blue for science. The rank insignia was displayed by silver bands on the sleeve, but with a thinner secondary band, for the ranks of lieutenant commander and captain.

The Starfleet insignia was the delta/arrowhead design for all personnel. ()

By the 24th century of the alternate reality, Starfleet had adopted a uniform similar to the ones used from the 2350s to the 2370s of the prime timeline. ()

Duty uniforms

Fleet uniform

Type A 

The duty uniform consisted of a black undershirt, and a colored overshirt featuring the officer's division color and the Starfleet insignia. Rank stripes were displayed on the sleeves. Charcoal grey pants and boots were issued with the uniform. This uniform was only used aboard starships, and not at Starfleet Command or on Starbases. (; )

This uniform was in use by at least 2255. ()

Type A skirt 
Female officers could wear either a uniform similar to the standard male uniform or alternatively a short-skirted uniform not dissimilar to the prime universe equivalent – which itself had two variations, one with no sleeves and one with full sleeves. Without the sleeves however, these dresses did not display the ranks of each officer on them.  Unlike the uniforms of the prime reality, which always wore the skirt style uniform with black stockings, the alternate reality uniform was designed to be worn bare-legged without hosiery. (; )

Type B 

By 2263, Starfleet introduced a new style. Much like the Type A uniforms, the standard duty uniform consisted of a collared shirt with a division color, yellow, blue, or red, a pair of black pants and black boots. Unlike the previous design, it lacked the detail of the sewn-in Starfleet insignias in the fabric. ()

Type B skirt 
()

2379
By the year 2379, the standard duty uniform had become nearly, if not entirely, identical to the uniform worn in the prime timeline in the early 2360s: division-colored piping along the neckline and collarbone, black shoulders, division-colored torso, and a combadge with a round base displaying the Starfleet insignia. ()

Starbase uniform 
By 2263, the uniform being used at starbases like Yorktown bore some resemblance with the one from the mid 2160s. Unlike the previous one though, it sported the rank insignia at the neck collar. ()

Flag officer uniforms

Flag officer duty uniform 

The flag officer uniform was a two-piece outfit with dark gray pants and a white and dark gray flared jacket featuring a high collar. Rank was shown by both epaulets and sleeve stripes, and a gold Starfleet Command pin was worn on the chest. ()

Flag officer starbase uniform 

The starbase flag officer uniform was similar in overall style to the standard starbase uniform, but did sport several differences. Flag officers wore a dark grey/black shoulder color and had rank insignia on both arms as well as at the neck, so this uniform didn't have the built in display on the left arm. Flag officers also wore the solid gold cadet dress uniform Starfleet insignia as opposed to the silver fleet insignia. The belt and zippers were also different. ()

Undershirts

Type A 

Worn beneath the division colored shirt was a black undershirt bearing the Starfleet insignia, also in black. The undershirts also featured the arrowhead design present on the overshirt. (; )

Type B 
()

Underwear 

For use beneath their uniforms, Starfleet personnel had at their disposal specific undergarments. This underwear was a dark blue/green. (; )

Dress uniforms 
For formal gatherings, Starfleet personnel wore gray or brown uniforms with high collars accompanied by a traditional peaked cap with the Starfleet emblem. Rank insignia was displayed by the standard stripes on the cuffs and by black lozenges on the shoulders, the number of shoulder device corresponded to the pip system that was seen used on the uniforms from the 2150s. ()

Flag officer dress uniform 

Admirals wore uniforms with white collars and white pants. ()

Ceremonial dress uniform 

Ceremonial officers wore black uniforms with blue sashes, along with a five-pointed star similar to that seen on the Command Division insignia on the shoulders in place of rank. ()

Medical attire 

Medical personnel could wear a white overcoat instead of their division colored shirt. ()

Medical uniform 

Consisting of a short sleeved white shirt, apron, white pants, and white boots. ()

Skirt

Dress

Tunic 

A short sleeved grey "smock" tunic was also available for use. ()

Scrubs

Special use uniforms

Arctic gear 

For cold environments like the planet , officers were given appropriate wear including a hooded jacket, gloves, and boots. ()

Engineering suit 

A technician performing last-minute maintenance on Shuttle 89 was seen wearing blue coveralls. ()

Flight suits 

Introduced in 2259, these gray overalls were worn on shuttles. They had transparent yokes to show the division color, and the insignia was emblazoned on the upper arms. They could not be worn with the uniform skirt. ()

Hazmat suit 

Crewmen wore white hazardous materials suits to recover the irradiated body of Captain Kirk from his ship's warp core. ()

Orbital skydiving suit 

This EV suit was equipped with a parachute for orbital skydiving missions. The suit was available in all three division colors with a Starfleet insignia displayed prominently in the center of the chest piece and featured breathing equipment, including a helmet, for use outside of Class M environments. A communicator was placed in the left glove. ()

Thermal protection suit 

A copper armor-plated suit was used for inhospitable environments, such as the inside of a volcano. ()

Thruster suit 

In 2259, a thruster suit was available for extra-vehicular activity. ()

Survival gear 

Starfeet officers had access to survival gear as part of the equipment stored in Kelvin escape pods. This gear featured a dark blue jacket with the officer's division color on the shoulders, with matching gloves, boots, and pants. ()

Wetsuit 

Wetsuits came in two varieties: male crewmembers wore grey wetsuits with division colored piping, while female crewmembers wore designs with reversed colors (the primary color matching their division assignment; grey piping). The suits were also adorned with the same Starfleet insignia pattern as the regular duty uniforms.

These uniforms were equipped with engines placed on the ankles to propel the user through water at high speeds. ()

Starfleet Academy uniforms
Graduates of Starfleet Academy could wear the Starfleet Academy ring. (; )

Training uniform

While training on the Kobayashi Maru simulator at , cadets wore a simple blue-gray jumpsuit with the Starfleet insignia stenciled on the left chest, with no rank or class insignia. ()

Cadet officer dress uniform
Starfleet Academy cadets wore a red jumpsuit and jacket with a stand collar over a red turtleneck-like sweater; men and women wore pants while some women wore skirts. On both male and female designs, the Starfleet insignia was displayed prominently on the collar of the jacket. On some occasions, cadets wore a red cap with the uniform. ()

Standard service uniform
Fully commissioned officers working at Starfleet Headquarters, Starfleet Academy and archive facilities, and other ground installations wore a charcoal black standard uniform similar to cadet dress uniforms; instructors at Starfleet Academy also wore this uniform. Barracks officers and shuttle officers wore a variation of this uniform which included a black cap. (; )

Flag officer service uniform 

Admirals and flag officers wore a cream-and-grey uniform for regular, daily duties. Admiral  wore one such uniform when transferring command of the Enterprise to . Starfleet Command Admirals such as Richard Barnett wore a silver tunic without any division colors while serving on the Starfleet Academy Board in 2258. Other flag officers wore this uniform with a cap of the same design, featuring the Federation emblem on the front. ()

Section 31

Duty uniform 

Section 31 duty uniforms included a black shirt with a pale blue chest panel. They also wore the black dress uniform. ()

Flag officer uniform 

The flag officer's uniform was a variant of the duty uniform with dark black (with a blue stripe pants) and a uniform shirt. Rank was shown by sleeve stripes. ()

Assignment patches

Rank insignia

The insignia used in the 2250s consisted of silver bands worn on the lower sleeve of the uniforms of line officers, or gold bands for flag officers. Enlisted personnel and officers holding the rank of ensign wore no rank insignia.

Rank on dress uniforms was indicated with epaulets on their shoulders, ranging from one pin for ensigns, to five for admirals.

There was no apparent way for female officers wearing dresses to convey their ranks. (, )

Appendices

Appearances

Type A

Type B

2379 version

Background information 
The uniforms seen in the films Star Trek and Star Trek Into Darkness were designed by Michael Kaplan. The real-life explanation is that the uniforms seen in 2009's Star Trek were intended to associate the audience with the much more familiar Original Series uniforms seen through the late 1960s, in contrast to the pilot uniforms, which were only seen in two episodes. The filmmakers expressed surprise in Star Trek - The Art of the Film that the classic uniforms were never used in a film.

Kaplan explained that he selected red for the dress uniforms because of the strong patriotic feel the color gave. (Star Trek - The Art of the Film) In Into Darkness, Kaplan noted "There are a lot of high-powered meetings with Kirk and officers, and I wanted to add a level of sophistication, where – like any military service uniform – there would be different parts. So they now have dress uniforms, and shuttle suits, which they travel in." 

Sanja Milkovic Hays designed the uniforms in Star Trek Beyond.

Apocrypha 

Star Trek: Countdown to Darkness, Issue 2 depicts that the uniforms of the 2230s had phased out by, at least, 2239 in the alternate reality, and were replaced by this style. The only difference was that the command division was a slightly desaturated greenish-gold color. The comic book series also introduces a black excursion jacket to wear over the duty shirt, and a division colored apron.

In the   video game, Kirk and Spock don black-and-grey  to fly across a Gorn colony. The "wings" are green energy that are activated when skydiving.

External link
 

de:Sternenflottenuniform (Neue Zeitlinie)
ja:宇宙艦隊の制服（新時間軸2250年代）
Alternate reality
Starfleet uniform 11