Arnie.d said:
When I encode it for dvd with CCE SP I convert it to RGB and 0-255 colorspace. The resulting mpeg file has a greater range. The space will be black, the whites will be white and the color is a bit more distinct.

Something not quite right there. If you are capturing in YUY2, then you should not change the colourspace (unless, for example, you need to use a YV12-only filter in AviSynth). CCE will accept YUY2 input; you only need to convert to RGB if encoding with TMPGEnc.

If the luma range ends up wrong in the final encode, then you may have a wrong setting in CCE.