The "hero costume" was a tight spandex undershirt, with a cotton/spandex mock-turtleneck "t-shirt" which I believe fastened to the standard-issue wool-gabardine jumpsuit at the chest. When worn with an open "jacket", the turtleneck fastened to the trousers so as to keep both the shirt and the pants looking neat and crisp. I don't recall if the turtleneck was seen "untucked" at all. The undershirt was seen as a crew-neck tee or sleeveless depending on the actor (probably a male/female thing) in extremely disheveled situations, for example in Year of Hell Janeways uniform jacket got ruined by Neelix's Vogon Stew so she just went around in a tank top.
In Night, Janeway is shown in her short sleeve shirt and Chskotay in his short sleeve shirt to the elbows . Both shirts are unfitted. In 30 Days, Tom is shown in his shorter sleeved fitted shirt. In Juggernaut and Lineage, B'Elanna is shown in the fitted tank top.
I notice this a lot with the uniforms. The shoulders of the First Contact jackets are definitely grey in the films, but on television they sometimes look purple. Similarly the sciences division clearly wear blue at the beginning of TNG, but by the end of DS9 there has been an unspoken transition to green.
The evolution of uniforms in Star Trek: ST: ENTREPRISE ST: DISCOVERY ST: TOS: ST: TNG 1) 2) ST: DS9 1) 2) ST: VOYAGER (we can easily guess that once back on Earth, Starfleet officers will wear a grey uniform like their TNG & DS9's colleagues, right?!) Dress uniforms 1) 2) 3) 4) 5) (this white dress uniform is very classy! )
Thanks for putting that all together! I didn't watch Enterprise but it makes the Discovery blue palette more understandable now. Got to say though the pops of colour in the Original Series is just so Sixties and uplifting. I mentioned it earlier but I prefer the two tone uniforms to have mostly black but with the department colours near the top. As for the long tunic dress look - not a fan.
Shouldn't have been easy to change uniform on VOY, the UNiforms are likely replicated to start with. So you just replicate the new style slowly over a period of time as others get damged/worn out. Besides if you want to feel as if you are part of the fleet surely it would make sense to wear the style of uniform the rest of the Fleet is wearing.
They wouldn't have even known about the uniform changes until they got in communication with Earth again, several seasons in. ---- Responding to Ghislaine Braeme above, TNG had 3 uniform styles - in season three, the original uniform got stand up collars and the piping was removed. A minor change, but a change all the same.
Those first two TNG dress uniforms are just ridiculous looking and embarrassing. I liked the white ones seen in INS on and the TOS version too.