I've never liked them, far too Space-1999 for me. After TOS's colourful palate it just didn't feel right for Trek to me.
I agree!!! I liked that TOS's uniforms they were very colorful.
I think this idea could have come from color being added to B&W television. If you rewatch the original series, all the sets from the bridge, to sick bay, to the halls on board ship were all very colorful. This was great way to show the new look for television in 1966. I'm glad that they changed the uniforms in Star Trek II The Wrath of Khan,
it was a big improvement over The Motion Picture
type uniforms. I'm glad to see the previews for upcoming STAR TREK movie will return to the original look from TOS.