So i tested some thing with FFMPEG and with this parameter i get the correct colors:
But this is only for a already encoded video with Vegas, because Vegas somehow set the pc range flag?
So the solution is to tell the encoder that the input is in pc range if i understand the filter correct:
When i try to encode directly from the source file (No encoded Video from Vegas) i need to the the filter to:
-vf "scale=in_range=tv:out_range=tv" (It depends on the source file).
I don't know if this is possible to implement and if this is even the correct fix for this problem.