I CAN say for sure where the "artifacts" came from, and it wasn't technically compression related. Uncompressed 4:1:1 sampled video would suffer from the exact same problem. DV camcorders (American ones anyway, European PAL camcorders use the same color format as all DVDs) only record one color sample for every 4 luminance samples. So, when it comes time to play it back, if theres a 1 pixel wide bit of bright red surrounded by a a few pixels of some other color, the red will bleed through. In fact, only red, blue, and purple should have issues as the nature of YPbPr video recording means that the resulting green channel is basically full bandwidth. They do this because the human eye is most sensitive to green.

So, no, its not the DVD compression that did it. In fact I compressed the second set using pretty much identical parameters to what I did with the first set.