It think I will actually do a shot by shot CC on FOTR after I'm done with the SW DeEd BD. I did some tests and in some scenes, like the whole prolog for example, the colors of the FOTR BD are so different that it's nearly impossible to adjust them to look like the DVD without introducing ugly artifacts, so in those cases I'd put the chroma from the DVD over the luma of the BD - I already tried this out and it works pretty well but the framing is different, so even that approach requires shot to shot adjustments.

I also figured out a way to adjust the settings in MPC with ffdshow for when I watch the FOTR BD on my laptop, that doesn't bring it anywhere near the DVD colors but gets rid of the green tint and makes the colors more natural and makes the BD look much better.

Right click > Filters > ffdshow video decoder > properties

A window pops up and there I check the picture properties box and set:

Luminance gain:133

Luminance offset: 1

Gamma correction: 1.00 (off)

RGB gamma correction: 1.00 (off), 0.93, 0.97.

Hue: 0 (off)

Saturation: 64 (off) (one could decrease the saturation a bit depending on preference)

Colorize strength: 0

At the top, you can click Only right half and you can see the difference nicely in split screen.