Lt Charlene Masters was in blue, likely part of the high energy physics team, monitoring phasers in engineering, I think.
Lt-commander Mulhall appears to be assigned to engineering even though she was also the ship's exobiologist.
Lt McGivers was assigned to engineering (life support I think according to the novelisation) as the ship would not have a formal position for an Earth historian.
Other than that, the only other female engineer we hear about nearly blew up Scotty in Wolf in the Fold until the Motion Picture.
IMHO the costume department had to dress the female characters according to colored shirt compositions. A historian should have worn Science blue instead of red, as should have done Mulhall, whereas Masters should have been dressed the other way round.