f.lux is a simple program that alters the color temperature your computer’s monitor according to the time of day. During the day, your screen keeps the typical bright white look that you are used to. Once the sun sets, however, f.lux lowers the color temperature so that warmer reddish tones replace some of the bright whites and blues. The application’s developers suggest that this change may help you sleep by toning down the color temperatures you are exposed to before bed. Upon setup you simply let f.lux know your zip code so that it knows when the sun rises and sets in your area. You also let it know the type of lights you use in your room at night so that it can match the ambient color temperature of the room. I have it set so that the color change happens gradually over the course of an hour and I hardly ever notice it happening. If you prefer an abrupt change, you can set the software to make an instant switch.