To me they appear a lot better than the blu-ray, but that would not be too difficult.
There is some conversation in this thread:-
https://originaltrilogy.com/topic/4K-restoration-on-Star-Wars/id/16857/page/280
which goes into detail about the colors.
And also a bit in here: https://originaltrilogy.com/topic/StarWarsLegacycom-The-Official-Thread/id/1418/page/110 - which is worth checking out as well.