You'd need to isolate the original video stream and process it in an editor that had chroma adjustment capabilities. Vegas can do this sort of thing, but it would take a lot of your time (and, if you don't own Vegas, a lot of your money!). And when you'd done it you'd have to remux the whole thing back together again.
MackemX has the most elegant (and cheapest:)) solution.
Don't anticipate this feature in DVD2One some time soon. You wouldn't want to be hanging by the neck as long...