Useful for laptops with external displays connected. External displays
usually have an ability to adjust color temperature via built-in menu,
so you can run `wlsunset` exclusively for laptop's internal display.
Also different screens happen to look differently after setting the same
color temperature. Possibly has to do with the technology which
display is based on (TN or IPS).
Kelvin C
Artur Sinila
Kenny Levinsen