The color grading still needs some work IMO, but this is still incredibly impressive.
It’s pretty much just white balanced to the sprocket holes with a contrast adjustment, though some of the reels are balanced by hand IIRC.
There will be versions with “proper” color grades (Dr. Dre is working on one), but this is pretty much the colors exactly as they are on the print with any fading/color shifts cancelled out.
Actually, part of the hold up with the release was trying to do a “proper” color grade and no one agreeing on it!