Could it be that the color differences are due to print degradation (being it an old copy)?
I'm thinking of the "tint of yellow", the "saturated red", the "white lion"...
As for sound, did you notice whether the subjective breathing sound of Poole and Bowman comes from all the speakers or not? What about the low sound of the Discovery? In the MGM DVD, the former comes from all the speakers, while the latter does so only in the computer malfunction scene, if I remember well.