I know WMP has a tendency to crush blacks/whites so try another player like MPCHC or VLC; plus WMP sucks in general.
Are you exporting as MP4? I'd probably exporting it in another format since compression settings might be fucking it.
1. Those 2 screens with bad colors are from SV and MPCHC, the good one is a clean clip opened in WMP.
2. I rendered is as mp4 because it was supposed to be a beta just to show my friend how it would look like (it's 17 minutes vid). When I tried to render in .wmv I could see only some mixed colors (like on an old TV) on preview, so I didn't even try to render full version.
3. At first I thought that those colors are only broken on Vegas' preview but afterall after rendering it - those are still broken af.