Star Trek "Duty Uniform" Command Dept.      Command uniforms are worn by those who in a position, that will one day lead to the Admiralty, or the comamnd of a starship. Most command officers wear a mustard yellow, Captain Kirk almost always was seen in a "tea green" shirt
The Original Series was the first series of Star Trek, and as such, is the template for all later versions. Until the second movie, all the unforms seen were very similar in design. Following the movies, The Next Generation acted as a template.
Uniforms: Star Trek Uniforms: Duty, Command