Redshift adjusts the color temperature of your screen according to your surroundings. This may help your eyes hurt less if you are working in front of the screen at night. This program is inspired by f.lux.
$ sudo apt-get install redshift gtk-redshift
Open launcher (window button) type redshift and see magic. To quit it look into icon tray (bulb icon) click on it and quit.
Another way to launch it
Alt + F2 and type "redshift" in prompt.
- To close it or to toggle it, open terminal and type
$ sudo killall redshift