So in my Vegas20 project preview the colors look fine. The source file is a limited range bt709. Pixel format in Vegas is set to 8bit full.
However the rendered file from Voukoder looks sort of like there is a thin white layer on top, hard to explain. Kind of washed out.
The rendered file is also in limited range bt709 according to Mediainfo. I can only guess there is some miscommunication between Vegas and Voukoder?
I have tried frameserving the file with Cumincode Frameserver as well and I had to use this Avisynth script to make it look right:
.ConvertToYV12(matrix="pc.709").Tweak(bright=1, coring=false) and it ends up looking very close to the source.
But it being so expensive, I'd rather use this tool for my meager tasks.