Ok - what you're talking about is the video drivers artifically increasing the amount of colour each pixel has equally. So a RGB pixel with values of 100,100,140 would appear blue, and the video driver changes this to 101,101,141 or more probably something proportional. This is increasing gamma. I don't know how to do this in delphi. You would have to call a function in the windows API most probably. Have a search in google, or on Microsoft's site. Try and get a code snipped regardless of it's language, because it will be the same call in Delphi.