pittrek said:

First of all - what are you trying to accomplish ? Are you trying to re-create the ORIGINAL colours of the theatrical version or are you trying to get colours which will "feel" correct ?

To me the aim would be the original colours - what the film looked like on the film inside the camera, not what it looked like in the real world outside the camera.

But thinking about what the real world looked like outside the camera might help in working back to what ended up in the camera by deduction.