I don’t actually know the answer, but… What is your preference for look? Do you want it to look how it did on television taking into account studio lighting and film-stock and whatnot? Or do you want the closest to the real in-person paint color? Given that grey is especially susceptible to color-shifting based on these variables, real might not look right.
My preference is usually to find the real-world answer. As far as that is concerned, the best reference would be the command chair and helm in the Seattle museum. I don’t know if they are all in original paint, but given how banged up they are, I might assume so. At least one person who posts here, @tosgraphics , was part of a group that examined and fixed up the set pieces for display. I would be very surprised if they didn’t take the opportunity to compare their paintwork to modern paint chips. As the other issue is that usually vintage paints are no longer available, of course.
So, maybe he’ll chime in with some ideas. You can at least get the grey, black, and red/orange off those surviving pieces.