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.
Samsung 78" JS8600, Mits WD-92840 43" Samsung 43ku7000 - Lumagen Radiance XS, Martin Logan Motion 40s, Ascend Sierra 2s
58" Panny Plasma -DVDO DUO, Usher S520, JBL HLS-610, Definitive SM45, MusicHall Marimba