I think it's important to remember too that just because the skin tones look "unnatural" in certain scenes, or certain scenes are biased towards tan or green, or are much whiter, that doesn't mean that's not how it was. These kinds of colorings and "pushing" the film and etc. would have been done in the lab, which in those days was much more advanced than it is now (the 70s equivalent of computer color grading today).

The colors would never have been on the original negative as it was shot, but they were deliberate decisions that you lose when you go back to the original negative and start over again (the special editions besides the 97 which was sourced off of GL's technicolor print from 1977- and also looked radically different between theater and home video). Also, I think that on VHS versions they color corrected it greatly as they did with other releases.