Pretty much agree with zee944 about the two screenshot comparisons, the original screencaps looks better in both IMHO for pretty much the reasons he stated.
In terms of the DCP's colours though, I don't agree that the colours are fine, I personally find everything too red. The colours of the DVD release are much better IMHO so one of my next releases will be the DCP transfer regraded to closely match the colours and fleshtones of the DVD release of Back to the Future.