I just want to know more about Kirk's clothes. Does he wear them all the time? Does he ever wear colors other than yellow? Yellow looks good on him.
James Tiberius Kirk has had a wide variety of uniforms over the years;
Classic Uniform Kirk as seen in many TOS episodes;
Green Tunic Kirk as seen in "Trouble With Tribbles"
Dress Uniform Kirk from "Journey to Babel"
Evil Kirk worn in "Mirror, Mirror"
Two-Tone Kirk from "Star Trek : The Motion Pic ture"
Open Blazer Kirk from "Star Trek 2: The Wrath of Khan"
Cold Weather Kirk from "Star Trek 2 : The Wrath of Khan"
White Tunic Kirk
Odd Wifebeater Kirk from "Star Trek : Generations"
Large black V-neck Kirk from "Star Trek : The Animated Series"
And of course, ladies favourite - Shirtless Kirk...
You can find more information here
In the TOS-era, the Captain's tunic was actually green, with yellow marks near the wrists - this is a wraparound tunic:
Here's Kirk in a standard style green tunic:
I read, in one of the first Star Trek fan books back in the early 70s, that ALL of Kirk's tunics were Command Gold, but that a film processing error turned his Gold tunic Green in several episodes.