I would guess that the other films have the same issues, though I haven’t taken the time to investigate it. There are certainly plenty of color errors and missing gradients from just a cursory watching of Empire.

That said, it’s still an open question whether I’ll do the other films at all. Since Star Wars was the only one to be done in the Technicolor process, there’s the argument to be made that it should be the only one that looks like this, and I wouldn’t have any certainty about the colors of Empire or Jedi. In any case, it will be a long time before you hear about them from me, and by that time there will hopefully be an official or fanmade restoration that renders such work irrelevant.