16 bits is more than 65.000 colors. The maximum is 24 bits (hig colors). 256 bits is nonsense, 256 colors is less then you have now (unless you've got 16 colors, not 16 bits). So your problem isn't clear to me (nor to you, I think).
What happens if you change the color settings in Device Manager?
If you're looking for a driver (which is unclear) you're looking for the Win 2000 pro driver for your videocard. And if you don't tell what videocard you have, we here don't know it either. Find it in the manuals that came with the hardware, in Device Manager, or with belarc (http://www.belarc.com/Download-auto.html).
Then, if you know it, visit the manufacturers site for the driver.
Hope this helps.
Some how I lost the rest of my color. Have only 16 bits ,I had 256, what do I do? I know how to down load drivers on aol but have no idea what driver I am looking for. I am running win 2000 prof