I know some people have had success with avisynth filters like this: http://forum.doom9.org/showthread.php?t=96308
But I couldn’t begin to tell you how to do it. If you do end up doing this I’d be very interested in an unedited version of the Blu-Ray with the color correction applied.
I’d also encourage you to use the Blu-Ray of ROTS because I think it looks higher quality as well.