Ok, to address the original issues, and clear up some misconceptions.
It is essential that if anyone is going to post colour adjustments here (e.g. boost cyan by 20% and it looks better) that their monitor is calibrated. Otherwise, it is entirely pointless. Also understand that windows colour calibration does not calibrate ‘overlay’ video, so your media player or editing software may still not be calibrated even if you calibrate your Nvidia drivers. You need to calibrate the software being used, which is why professional setups have an output card, driving a broadcast monitor that is calibrated separately, to get away from the windows colour management minefield.
Sure you can say that these two sources look different, even on an uncalibrated monitor, but suggesting adjustments when running an uncalibrated setup is completely and utterly pointless. It is the same as saying that the Star Wars sound track sounds better, and is corrected by turning the bass up on your particular home stereo system, by 15%. It is meaningless to anyone else, unless your system is calibrated to a known standard.
You can’t give out audio adjustment advice to all and sundry by listening and adjusting on your boom-box. You would only be boosting the bass to correct for the crappy bass reproduction of your speakers. It would sound way to boomy on a properly calibrated audio setup.
In the same way, you can’t give out numerical colour adjustment advice without calibrating your monitor. Saying “A 45% shift in cyan is huge” is pointless. Your monitor might be out by 30% in cyan. All you can see without calibration is relative changes between different versions. What looks grey on your monitor might look quite yellow on one that is setup correctly.
Star Wars and its colour grade.
The original movie that was released in 1977, be it on Kodak or Technicolor stock, was a bit of a mess colour-grade wise.
The film was massively rushed, particularly towards the end. It had quite a few composite shots, and was shot on varying film stock and even formats. The result is the grade is pretty awful, even shot-to-shot balancing isn’t great in some scenes. This is how the movie was, and if you want to see how it looked upon release, then you will see a lot of colour variance between scenes, black levels that are all over the place, and shots that don’t match from moment to moment. Star Wars was also changed radically in the final edit, with scenes that were meant to take place at one point in time, being shifted to a completely different time, and again, not graded to fit all that well. It was a limitation of the technology, the tight budget and the lack of time.
Looking at scans of the Tech print is also kind of pointless. A professional scan gives a very flat, logarithmic image that looks nothing like the print. You need to project the print and grade the scan to the print. If you haven’t seen the film projected, you have no idea what the colour actually looked like.
The various home editions of Star Wars
The telecine process is completely different to the release prints. The home releases were done on telecine equipment, with the main aim of keeping the exposure within legal NTSC ranges. Not a ton of work was done other than to try and get skin-tones to look right, and to get the exposure within limits. So you get quite a different experience to the cinema, some explosions have more detail in the home release, as they are less blown out, due to the telecine operator adjusting exposure on the fly. The colour and exposure of the home releases have no real correlation to the original films, or even what the intention may or may not have been for the cinematic release. It was down to the telecine operator, on the day, working in realtime, to their own experience of making it look good for VHS, Beta, CED, VHD, LD etc.
Again, just to be clear, the look on home video has no correlation to the film release, telecine is a totally different process, and done by an operator with different goals and tools.
The Special Editions on film
The film versions of the Special Editions are not far off the original film releases as far as colour goes. No lobster faces, no over saturation, but not a lot of change to the colour grade.
The Special Editions on home releases.
This is where it gets problematic. Again, people assume “STAR WARS” they will get the best in the business to do the colour grade, and spend lots of time, money and love on it.
Sadly, not so. The colour grade was rushed, and the tools used were new, and mistakes were made. This was the first time the film was fully digitally graded, and there were many problems along the way.
In trying to adjust for the faded source, they pushed the reds a bit hard, and you get lobster faces and other issues. In attempting to make the film more palatable to a 21st century audience, along with the scrubbed grain, we got crushed blacks, saturated colours and in places a weird palette. Again, due to time and money constraints, the job done was patchy, and the SE BD and DVD releases don’t resemble the original or the theatrical releases very much as far as colour goes.
So in short, yes, each release has varying colour. If you want to know what the original colours actually were, then watch it on film, and you will find that the colour is all over the place.
Looking at costumes, original artwork and set photos is interesting and informative, but ultimately gives no guide as to what was actually on-screen or intended to be on screen. The set photo might have everything looking balanced, and the neg also might be balanced, but the release print, for that particular scene might have been shifted towards blue, and may have been shifted intentionally. That is literally the job of the colourist, to change the colour in the captured scene to tell a story, so of course it is likely that set photos and costumes will look different to what is on screen in the final movie.
Where does this leave us?
Well, Star Wars was badly flawed upon release in 1977, and every release since has been badly flawed as far as colour grading goes. If you are interested in how the film actually looked, then you can watch it on film and find out.
If you are more interested in watching something that suits your own personal taste as to how a film should look to you then it will really be down to making your own grade, to suit your own expectations/enjoyment. At that point, worrying about the original colours, intentions, or why differing versions are different is completely moot. Just get on and make the version that floats your own personal boat.