I’ve re-read your last post a few times, and I’m not 100% sure what you’re getting at, but I think I get the gist.
Yes, on older film, grading was problematic. As a colourist, you would sit in the screening room with the DoP and the Director and sometimes a few others, and you would make notes as the film played, depending on feedback from the two Directors.
The notes you were making were the place in the film, and the adjustments you were going to make to the film development process to adjust the colour balance the way they wanted it. You had to be able to see it in your mind, and then immediately translate it to temperatures and times, you effectively had three buttons as a colourist, plus exposure. You had to know and visualise everything in your head, make notes, then punch it all out, a new print would be struck and often the next day you would sit again with the Directors and they would ask for a few more changes or not.
Star Wars was on a very tight budget, both in money and time, there wasn’t much time for grading, plus it was shot very quickly, all over the place, and on a multitude of different stocks, and then the composites… in short, the grade is all over the place, and often varies from shot to shot.
So yeah, in the sunset scene, each shot is not correctly balanced to each other shot, this is the case in a lot of scenes in Star Wars, less so in Empire and much less so in Jedi (apart from the comps).
This is the way the film was.
When it came to home releases, the VHS release was colour timed by the telecine operator, quite possibly with no input from anyone, and their main aim would have been keeping the exposure within legal video limits, and making sure you can see what is going on. They look radically different to the film in some places.
When it came to DVD and then later Blu-ray, digital grading was possible, so isolating parts of the image to achieve a different look became possible, and the grade was completely removed from the original film.
As to what is ‘true’, well that is the original film, warts and all. It may not have been exactly what Lucas ‘wanted’, but it is what he signed off on, and what the world saw.
As for intent, that is a slippery slope. They all no doubt intended for the creatures in the Cantina to be fully articulated and way more realistic. They probably wanted everything to look a lot better than it did.
Chasing intent is impossible, the intent would have changed between shooting it and seeing it in dailies. The intent would change with hindsight, with life experience, with the changing world and society and technology.
There is no real way to gauge intent, only what was actually done, i.e. what is on the film.
Everything else is a revisionist version. Personally I would prefer to watch a better colour balanced version than what is on the original Star Wars, with consistent black levels, consistent colour shot to shot, and some of the colour glitches fixed. But I also know the need to preserve the film as it was, and the importance of that.
Which is why I personally make an archival version, then an ‘adjusted’ version that is more like the aesthetic that pleases my 2018 self, and lets me watch the film the way I remember it, without 70s glitchiness that pulls me out of the experience, and lets me enjoy the wonder again, safe in the knowledge that the original is preserved, to be studied and enjoyed in all its warty glory 😃
TLDR: Yes, the grade is all over the place, every different version will have different colour.