This has flashing back to my own rudimentary attempts at color adjustment.

You can never get exactly what appeared in the original theatrical presentations. It's just a matter of playing around until you can produce something about as good or maybe even improved (for a different format.)

I never had the equipment or could go very far.

Contrast and brightness was always a big question mark. "Do we really need the darkest 5 or 6 degrees, or the brightest 5 or 6?" "Does it get too muddy?" "Could they be left in the mid-range to avoid constant readjustment?"

Edge adjustments and drops might not be as useful as picking middle range and getting simple and clear edges.

I simplified down to five degrees of adjustment for each and then tried a sort of color reversed OTTO (or OTOT) to get 10. I didn't know whether I wanted to play with that many different parameters and I was afraid that 10 could increase my difficulties exponentially.

In short, I didn't really know what I was doing.

I'll leave it to the pros.