Upper right corner - for me personally looks the best as far as details go, its one major flaw being the scene in which Piett approaches Vader while he is in his hyperbaric chamber which is way too sepia-toned.

Upper left corner - too washed out, too wobbly and too much loss of detail.

Lower left corner - too dark, it is however the one with most accurate colour palette in the Vader hypebaric chamber scene as far as I'm concerned.

Lower right corner - too blue.

Winner: Upper right corner, the most detailed of the four, only needs to have the sepia/orange corrected.