Harmy said:

This is quite easy actually, the original colors are those the director and the DP would have seen when viewing the dailies and doing the color-timing and since they would have used the same warm bulb, which was the standard back then, it is quite clear they would have seen the warmer colors.

Ha! I was wondering if we could pull you kicking and screaming back to this thread! But seriously, I agree. But I think there is some intangible value to the colors viewed with neutral lighting (because it may more accurately represent the colors that existed in the set, but were washed away by the biased projector bulb), I'm just not sure what exactly to name that quality.