I've noticed that the brightness of computer monitors drastically varies between computers. As such, this changes the look of web pages greatly. Is there a way to use JavaScript to automatically detect how bright (or dark) a users monitor is so that I can adjust my web page colors accordingly? UPDATE Please note that I do not want manual user involvement. I want this detection to be automatic so that users don't realize I dynamically change the color palette automatically based on the brightness/darkness of their monitor.