The Starfleet uniform of the alternate reality, along with many other changes in the timeline, experienced a slight change due to the temporal incursion by the renegade Romulan Nero. As a result of these changes, which included the premature death of George Kirk and the destruction of the USS Kelvin, Starfleet by the mid 2250s was using a different uniform in the alternate reality than the original uniforms which had been seen in the prime timeline.
As early as 2255, Starfleet was using the same "red/gold/blue" shirt design which in the prime reality was not introduced until at least 2266. The rank insignia had also changed slightly, consisting of silver bands on the sleeve, but with a thinner secondary band, rather than the previously used "hashmarks", for the ranks of lieutenant commander and captain.
The Starfleet insignia of the alternate reality was the delta/arrowhead design for all personnel, contrasted with multiple unique assignment patches for different ships and bases in the "prime" reality at around the same time. (Star Trek: The Original Series; Star Trek: The Motion Picture; Star Trek)
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. Unlike other duty uniforms, this uniform was only used aboard starships, and not at Starfleet Command or on Starbases. (Star Trek; Star Trek Into Darkness)
Type A skirt
Female officers could wear either a uniform similar to the standard male uniform or alternatively short-skirted uniform not dissimilar from 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 rankings of each officer on them. (Star Trek; Star Trek Into Darkness)
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. (Star Trek Beyond)
Type B skirt
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. (Star Trek Into Darkness)
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. (Star Trek Beyond)
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. (Star Trek, Star Trek Into Darkness)
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. (Star Trek Into Darkness)
Flag officer dress uniform
Admirals wore uniforms with white collars and white pants. (Star Trek)
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. (Star Trek Into Darkness)
Medical personnel could wear a white overcoat instead of their division colored shirt. (Star Trek)
Consisting of a short sleeved white shirt, apron, white pants, and white boots. (Star Trek)
A short sleeved grey "smock" tunic was also available for use. (Star Trek Into Darkness)
Special use uniforms
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. (Star Trek Into Darkness)
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. (Star Trek)
Thermal protection suit
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. (Star Trek Beyond)
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. (Star Trek Into Darkness)
Starfleet Academy uniforms
While training on the Kobayashi Maru simulator at Starfleet Academy, cadets wore a simple blue-gray jumpsuit with the Starfleet insignia stenciled on the left chest, with no rank or class insignia. (Star Trek)
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. (Star Trek)
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. (Star Trek; Star Trek Into Darkness)
Flag officer service uniform
Admirals and flag officers wore a cream-and-grey uniform for regular, daily duties. Admiral Christopher Pike wore one such uniform when transferring command of the Enterprise to James T. Kirk. 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. (Star Trek)
Flag officer uniform
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.
|Starfleet uniform styles|
|By era:|| 2140s-Early 2160s • Mid 2160s • 2230s • Late 2230s-2250s • 2250s-Early 2270s • Mid 2270s •|
Late 2270s-2350s • 2350s-2370s • Late 2360s-Early 2370s • 2370s • 2380s • 2390s
|By type:|| Casual duty attire • Patient wear • Fictional uniforms|
Alternate & parallel uniforms • Alternate reality uniforms • Terran Empire uniforms
|Related topics:|| Assignment patch • Federation blue • MACO uniform and equipment • Starfleet decorations •|
Starfleet insignia • Starfleet ranks • Terran Empire ranks • Xenylon • Uniforms of the Alpha Quadrant
The uniforms seen in the films Star Trek and Star Trek Into Darkness were designed by Michael Kaplan. They are quite different from the pilot uniforms seen in "The Cage" and "Where No Man Has Gone Before". It can be assumed that Nero's time tampering had something to do with the shift, although the real-life explanation is that the uniforms seen in 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. A similar situation arose in "Friday's Child" where Leonard McCoy is shown in a flashback video wearing an Enterprise tunic whereas, historically, he should have been wearing an earlier pilot episode uniform. 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.
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.