zombie84 said:

It's a matter of evidence. As you said, no one can know 100%--not even George Lucas and the DPs of the films. So you have to go external.

There is ample evidence to indicate the bolder colour choices are what the film looked like.

There is even more evidence to indicate that Mark Hamill was not bright orange during the making of the film. This stuff gets so damn subjective that the reference point that makes the most sense to me is skin tones. We pretty much know what white people's skin looks like, and if the characters end up looking like they're wearing spray on tan I don't care how much evidence supports those levels. I don't know shit about this stuff, but I do know when skin tones look weird, it's hard not be distracted by that.