You can adjust the color of the uniforms with lighting, just like they behaved on-set during production.
Tungsten light will make it grey, and it is usually grey after sun down.
I love this phenomenon, and I really appreciate your insistence on making the uniforms in their actual colors. That makes these figures all the more authentic, and thus valuable. 1/6th scale museum pieces.
The uniform debate feels like Michael Myers' Charcoal Grey Coveralls.
Some say its Navy Blue others say its Spruce Green but according to John Carpenter it was Charcoal Grey. Their is still a ton of debate on it and it all came down to lighting and tv set resolution.
The QMx Kirk is a prime example.
Nanjin managed to find the perfect material that reacted like the actual shirt, so that under different lighting the figure's shirt changes from green to gold.
There was a lot of anger about the coveralls included in Trick or Treat Studio's '78 Halloween Accessory Set. They were advertised as 'Spruce green' (described in the original Sears catalogue as 'medium green'), yet appeared to be more grey.
Yet I found under different lighting conditions TOTS had found a chameleon material, varying from blue-grey through grey to green-grey. I found the perfect position, with the right light turned on, where the figure looks just like he's wearing 'Tex green' (described by Sears as 'gray-green'), which is just right to me. In other light it can turn more blue, or charcoal, just as in the film.
People who even worked on the
Halloween film can't agree what colour they were, because the coveralls must've been so sensitive to changes in light.
It sounds like Nanjin's found the perfect material for TMP Kirk, able to represent both the green-grey and grey examples on film depending on your own lighting set up.
I found this on Memory Alpha:
The Making of Star Trek: The Motion Picture (p. 125) identified this uniform as an example of a "loden green" (rather than gray) "dress uniform."
In the alternate reality, by 2258 admirals wore a uniform and dress uniform similar to this. In the book Star Trek - The Art of the Film, Star Trek costume designer Michael Kaplan stated that the resemblance was intentional.
Even when you search for "Loden green", the colour swatches that come up on Google don't even match each other. Add to that the fact that colours are dependent on your own screen/monitor set up, and the whole colour debate is pretty controversial, and very hard to settle.
As Nanjin has written numerous times before, if someone asks for "screen accurate" it all depends on the screen they watched it on. Hence I think 'prop accurate' is the safest bet, and if you find it doesn't suit you in hand you can try changing your light bulbs (e.g, LED warm to cool, or vice versa).