Is this limited to color, or could you change other attributes? Like running say 5 different shots through PFclean, then letting the learning algorithm try and degrain based on the results.
Or using it to combine different sources- say you have two different sources, but one has more picture on the left and right or top and bottom (Fellowship of the Rings theatrical vs extended)
You manually combine a variety of the frames, adding as much extra picture as possible without causing uneven letterbox borders. You train the algorithm to accept the 2 source images, and a reference image with them manually combined.