A couple of quick things to check.
First, if you open a DV file in QuickTime, make sure that the “high quality video” box is checked under visual settings.

Also, in my opinion, coloring DV (4:1:1) video with the 3-way color corrector makes the video look manipulated. It just feels like it’s been played with. I’d suggest using Color as it deals with the colors in a much more natural way.
-Russ
Russell Lasson
Colorist/Digital Cinema Specialist
Universal Post
Salt Lake City, UT