One thing that came to light when I was at the opening of the Frankfurt exhibit is that all 6 suits made for the film started out as the silver version. The whole TMA-1 sequence was filmed before any of the Discovery stuff. 5 of the suits (and their helmets) were painted-- red, yellow, blue, green and violet (which we never saw). This left only one suit and helmet in the original Lunar scheme (silver suit, white helmet).
After all the first unit stuff was shot, they moved on to the stunt work and whichever suit fit the stuntman got painted for both Bowman and Poole. During the editing of the film, Bob McCall delivered the artwork for the posters, including a scene he envisioned-- the survey team on an overlook of Clavius Base. Kubrick decided that needed to be shot and added to the Aries landing sequence, so they painted three suits back to silver and shot the scene. It is the only scene in the film shot at MGM in Los Angeles. You can see at least one of the guys has the arm panel on his suit. It is unclear if all the suits wound up in Los Angeles or if only 3 wound up there.
The suit that is on display in the exhibit, which is still traveling, is silver, but also shows bits of green, red and yellow. It is interesting to note that only 3 of the suits have survived the film-- Greg Jein's, Kubrick's and the one that sold on ebay last year. And they are all silver.
I went through my photos of the exhibit, but could not find one of the silver suit. As I recall, it was behind plexiglass and the reflections were really bad, so I didn't bother. But, here's a shot most of you have not seen--
This was one of the production stills on display, which for some odd reason didn't have any reflections on it! And here's a shot of the red helmet--
Scott