I want to ask a few question first....Are you trying to adjust color settings on the monitor itself instead of through the Nvidia control panel?
Did you go to the Nvidia support site and download the latest drivers for that card setup?
When you download the latest drivers, part of the download package is an updated Nvidia Control Panel that is accessable by right clicking on the desktop and scrolling down the drop down menu and choosing "Nvidia Control Panel". In this control panel is where all the different color, contrast, gamma etc. settings are made as well as letting the machine or the software make the choices.
Below is the link to the Nvidia support site. I will try to locate the latest drivers for your card and put that link below. Just copy and paste the link below to the address bar of your internet browser and hit enter and it will take you right to it.
If need more guidance, just send me a message.
When you click on the link below or copy and paste, click on the download button, then click that you agree to the terms. A save window will come up, in the left pane click on the desktop icon and then click on the save button. This will save the file directly to the desktop. Simply doubleclick on the installer file and the program and drivers will install.
http://www.nvidia.com/object/winxp-257.21-whql-driver.html