Harmy said:

The colourtiming process was much more difficult then than it is today with digital technology and that's why it couldn't be as perfect as today.

If, by "perfect", you mean "cyan and orange"...

Part of the appeal of pre-digital movies for me is that colors vary almost entirely because of the lighting, just like the real world. Sure some weird lighting can occasionally make skin tones look greenish or grayish, but that's just like the real world too. I actually enjoy that. It's much preferable to having consistent skin tones inside, outside, under flourescent lights, standing next to a big red banner, etc.