Sciences division
The sciences division was the corps of officers and crewmen within Starfleet who specialized in both scientific and medical research and control functions on starbases, aboard starships, and at Starfleet Command.

Duties 
Members of the sciences division specialized in sensors, research, theoretical and physical laboratory work, biological studies, and also worked as technicians, medics, and surgeons.

Officers within this division were mostly limited to scientific or medical assignments such as doctors, nurses, and scientists working in a variety of disciplines. These officers served as department heads such as chief medical officers and head science officers. Opportunities for command assignments were somewhat limited for these officers due to their lack of overall command experience and training. However, officers who had taken and passed the Bridge Officer's Test could be promoted in rank to commander and were certified to command a starship, if necessary. In most instances, however, science division officers would only take command of a ship or starbase in the absence of other senior officers due to circumstances such as an emergency, illness of a commanding officer, or manpower shortages as may have occurred in wartime, for example. Additionally, these officers could fill the role of executive officer where needed. Jadzia Dax, for instance, took over as XO and then commander of the  during the Dominion War when the situation required it. (; )

Members of the sciences division belonged to such  as astrometrics, astrophysics, astrosciences, geophysics, hydroponics, planetary geosciences, quantum mechanics, and stellar cartography.

Uniforms 
Officers who belonged to the sciences division sometimes wore the division color of a department other than that in which they specialized. () For example, if a science officer became a department head, they might have worn the colors of command division, or if they had a dual specialty in an operations division department, an alternate color might have been worn. ()

Beginning with the Earth Starfleet of the 2140s and 2150s, line officers and noncoms of science division wore blue-division stripes on their uniforms. This use of blue continued through several uniform styles until the 2260s. On starships, such as the , science-division crewmembers had a specialty insignia in their insignia patch, a circle with two longitudinal lines dividing it.

By the 2270s, new uniforms showed different division colors, with medical spun off into its own division. Science-research and technical staff wore orange behind their Starfleet badge, on uniform bands, accessories, and epaulets. Medical crew wore green badge backings and accessories.

The colors were changed again with the 2280s uniforms, with green continuing to represent medical personnel, and science and technical staff wearing gray trim. The insignia used gave the officer the option of wearing command-division, white-uniform insignia, with another department color like sciences' banded across, or the opposite, with department-color insignia (green or grey, in this case) with command-white banded across.

On the uniforms used from 2350s onward, blue had again become the sciences division color, and medical had been re-absorbed into sciences. 

The second variant of the 2371 uniform, while still referred to as blue, was actually a shade of teal, a mix of blue and green. The color was later applied to the 2373 uniforms as well.
The uniforms used in the 2380s and 2390s returned to a true blue for sciences division.

Gallery

Science division officers

Background information 
During , sciences blue first appeared in  and was regularly worn by the science station officers, medical personnel, and security personnel who later wore red after 2265. () Science Officer Spock wore sciences blue, although he briefly wore command gold for his dual position as executive officer. () Some scientists (like astrobiologist Ann Mulhall and historian Marla McGivers) even wore operations red, suggesting they had more operational primary duties. The work coveralls were muted variations in the pilots from the duty uniforms and were light blue in color. Later they matched the blue of the standard duty uniform.

In the movie era, costume designer Robert Fletcher added several different uniform colors, breaking the traditional three departments into six.  featured Spock wearing orange trim denoting Science and McCoy wearing the bright green of Medical. When Fletcher redesigned the uniforms for , he continued to keep the two departments separate, with McCoy and other medical personnel in green and science officers now wearing grey.

At certain periods of time, roles such as Communications and Navigation have been shuffled between divisions.  One notable example is Hoshi Sato who wore a blue uniform in her role of communications officer. From  through Star Trek VI: The Undiscovered Country, both Nyota Uhura and Pavel Chekov wore uniforms with science grey trim.

The decision to switch the meaning of the colors for command and ops divisions between the TOS and  uniform styles was made in pre-production of . However, the TOS blue was kept as the sciences division color.

Most often, in the Federation Starfleet, captains and admirals wore command division colors; however there were exceptions, which proves that this was not a requirement. In TOS, Captain Krasnovsky wore a science blue dress uniform, the only captain in Trek to ever do so.

See also
Science departments
Starfleet Science
Starfleet
Science
Groups