Every TV's 3D quality is different and is dependent on the TV manufacturer. There is no way to globally change settings for all games since games are so different in color values. You can try to get a contrast setting that is a good balance for most games. You can experiment with improve 3D imaging settings to improve image quality. NVIDIA recommends adjusting the settings in the priority order below.
1) Adjust contrast in game (providing options are there)
2) Adjust contrast in game and fine adjust in TV (make sure to adjust game first)
3) Adjust contrast in TV