From what I’ve seen, the prints for ROTJ have different color leanings. The one used for 4k83 evidently is NOT on lowfade stock. The release prints that are on lowfade stock (LPP) look more blue and the colors are similar to the more familiar home video. From the GOUT, which is also from a 2nd generation print (an interpositive struck in the mid 80’s), the blue tint of the lowfade prints is more accurate than this. This print might have better resolution, but might not be the best color source for the film. It is not what you would remember from the theater in 1983.
Where do things like the eralier restorations fit in? Stuff like Pugo (I haven’t yet tracked it down) or SSE