Atrocious or not they are actually a pretty close match to the Technicolor IB print that is viewed as a reliable color reference, right down to the greenish color of the Death Star walls:
http://screenshotcomparison.com/comparison/138323
http://screenshotcomparison.com/comparison/138324
http://screenshotcomparison.com/comparison/138325
http://screenshotcomparison.com/comparison/138326
http://screenshotcomparison.com/comparison/138327
http://screenshotcomparison.com/comparison/138328
http://screenshotcomparison.com/comparison/138329
http://screenshotcomparison.com/comparison/138331
It would be interesting to see how such a color correction would look on a true hi-def source, but from these caps I would say it is definitely possible to do a pretty accurate color correction from a single frame. I mean the frame a used as a reference wasn't even from the same print.
Update: I noticed some of the frames in the Technicolor IB are not exactly the same, but I guess I got my point across.