There were two dye transfer processes.

One use Matrix Film which was blue sensitive only and required a set of separation negatives made from an original transparency. It also required contrast and color correction masks in many cases. This is the process re-created by Jim Browning, which is excellent BTW.

The second uses Pan Matrix Film which is pancrhomatic and which prepares the mats directly from color negatives in one step. This is the process used by Ctein.

Both Jim and Ctein are great creative artists and masters of analog color printing.