Nvida color gamut is a mess. You will need to calibrate the TV again with the Nvidia PC as a source.
Hopefully you have enough CMS memories on the TV to support such an endeavour.
You will need a Blu-Ray playback application and something like the AVS HD 709 disc. Grayscale will probably not require much tweaking, gamma, and color gamut are likely to be way off. I have to HTPCs one with intel and one with Nvida on the same TV. The intel is much closer to correct on color.
Nvida does Cyan very badly.
Mits WD-92840 92" DLP - Lumagen Radiance XS, Martin Logan Motion 40s, Ascend Sierra 2s
Older 58" Panny Plasma -DVDO DUO, JBL Studio 530
Pioneer AJs, PSB Images, Usher S520, JBL HLS-610, Definitive SM45, MusicHall Marimba