Every video transfer get's its own color timing, every newly printed interpositive get's its own color timing,
so what do you consider the original color timing then?
Every time you run the film through telecine machine,
you have to color correct the video data because film images are not really "compatible" with video,
so you need serious contrast corrections and color corrections. And there has to be someone
there to supervise the transfer, I supose Lucas was there every time (I don't think he would let anyone else
fine tune his films) and he made corrections.
The thing is that the raw interpositives have an orange low con image, and to view them you have
to correct them. Telecine machines have a default way of correcting this, and sort of emulating
print film contrast. But still there are numerous ways of rendering this raw footage.
There are 4 "flavours" for cinema print film today (2 Kodak, 1 Fuji, 1 AGFA) , each one has it's own
contrast, color etc. Therefore, not even direct one-light prints from a negative are objective.
And there have been a lot of print films in history, each with different look to it.
And as for video transfers, things are even more relative and subjective.
There IS NO "original" color balance and exposure setting.
The negative has over 10 stops of exposure, if you show all 10 you end up with a very very low contrast washed out image,
you can choose how many stops to show, and which stops to show.
The negative has an orange mask, and all the colors are way off to cyan-ish, a cyan-blueish nightmare to be exact.
So chose your color balance because the original color balance is unwatchable.
There IS NO standard way of rendering this raw footage. Each print film has it's own
way, and each telecine transfer is a matter of choice and taste.
I guess if you consider the original color balance and contrast, that which was in the
prints in 1977, then you are in trouble because where will you find a non-faded SW
print today, or a SW print at all. The only surviving evidence of original color timing today
are a few Technicolor prints made in 1977, Lucas has one, Gary Kurtz had one etc.
These never fade and are a good color timing reference.
But video transfers are very subjective by nature, and never show what is
on film really. video transfers are "subjective interpretations of film images" so to speak.
All you can do really is correct the images on your own taste, because there is no
way that you can see the original timing today.