f.lux is makes the color of your computer's display adapt to the time of day, warm at night and like sunlight during the day.
Black Light Pro lets you add visual effects on your screen to rest your eyes or to have fun. Setup your effects and switch when needed with a hotkey or at predetermined times, including sunrise or sunset.
Invert and make the screen all-red if you’re into astronomy. Tint with orange-yellow to help you sleep better, or blue to keep you awake.