It’s possible to get at least this far by calibrating with a known display chart.
I’ve written a little about that process (look at the giant triangle! 
) in this post. And then I eventually dug a little deeper over here. That second post includes all the links and command lines to turn one of those charts into an ICC (or Cube LUT) profile.
This gives you a nice, precise answer but the results are only valid when using the camera in the same lighting situation. Change the backlight and you’d need to recalibrate.
There’s also the question of metamerism. These calibration charts themselves are printed on a film stock with particular characteristics (and that only have so much possible color range). The closer that film stock is to what you’re actually scanning, the more useful the calibration. I got lucky: Wolf’s targets are printed on Ektachrome and half my footage is Ektachrome.
All of that said, there is a weakness here: at the end of all this effort you will be able to very accurately represent the now-faded colors in this old film. 
Any arbitrary changes you make to “restore” the color afterward make this whole process kind of academic since you’re not really using the calibration anymore. So, at best, I just treat it as a good starting point (mostly because I’m not using “normal” illumination).