I’m in the process of creating reference shots for the final color regrade. My process involves:

Do a rough correction of the Technicolor IB print reference frames.
Match a bluray frame to the corrected Technicolor IB print with the color matching algorithm. If necessary do another correction based on the Japanese Special Collection laserdisc, if the print reference has issues.
Correct anomalies in the corrected bluray frame, such as black levels, contrast, luminosity, and saturation, or unwanted color shifts.
Save the color reference.
When all color references are complete, do an automated color correction for each shot in the bluray.