Nvidia Control Panel Color Depth Options

Hi! I have a Samsung 2333HD monitor and 2 SLI'd 3GB GTX 580 GPU's. I was checking out the settings in the Nvidia control panel yesterday and noticed RGB color was set to 16-235, every time I update the drivers it reverts to that setting. Well I have had it that way for months and didn't realize it, so I switched to Full 0-255 and it made a night vs day difference! Played some (modded) Alien Isolation and the colors were way better! Then I noticed another setting today called "Output Color Depth" and it only has 8bpc as an option, while some others online seem to have 10,12 and 16 bpc options. I've heard something about this before when I read Alien Isolation was designed to support higher color depths. So I guess what I'm asking is what exactly is bpc and how do I get the higher settings? Do I need a better HDMI? Or does my monitor just stop at 8bpc?
I rarely game only playing occasionally every few weeks so I'm not to concerned whether or not my games support it. Though I use my PC daily to run an image slideshow and would like the best possible color.
Thanks guys!

Oh I should have mentioned the Nvidia Control Panel has a "Desktop Color Depth" option which is set to 32Bit, and then a "Output Color Depth" option which is set to 8bpc. I'm concerned about the "Output Color Depth".