Impossible to Reduce the color saturation ?

Does Someone has solution on how to adjust the color saturation of the overall desktop environment for LCD screens running with nvidia cards? DVI or d-sub does not matter.i did not Find any way to adjust the color saturation on the interface i m running. RGB settings on the screen does not make the colors less and less color-filled until they are completely black.

Overlay settings ( "Video & Television") has "saturation" adjustment, but not "adjust desktop color settings", which is only Gamma, Hue (graph), etc., not "saturation".

No one online seems to know how to do. Has Googled in for hours without success. I Chat with someone online who was the former ATI shareholders, and it was quite surprising when he could not change the saturation setting on his new nvidia cards. Catalyst settings apparently allowed this. If this is true, I do not know that .

Does anyone have solution to this problem?