40:32 mark (The shot continues through 40:33). In particular the first frame of the last shot of that scene (the wideshot of the entire homestead with Luke).
JEDIT: Whoa, that is very underexposed as well! My suspicions seem to be correct that the Tattooine stuff looks very different than the later releases.
There seems to be a lot of pink in the lights of the Obi-wan/Vader duel, especially compared to the GOUT. perhaps this is systemic?