Thank you for your answer. I've saw the example on NirSoft web site http://www.nirsoft.net/vc/change\_screen\_brightness.html where I can make the screen brighter or darker but how can increase or decrease the intensity of the red/green/blue components? For example: How can to increase only the blue component in all RGB values to add more blue color to the entire display? Robert.

What I know they are some sort of COM objects. Starter can be possibly http://www.opcfoundation.org/[^] but in fact I only heard that they exists, nothing more ;-) But I also heard that I'll about to develop some :-(