Redshift is an alternative to F.Lux on Linux.
Installing it is easy from the Ubuntu archives:
$ sudo apt install redshift-gtk
On older Ubuntu versions, it might not be available. In that case, install it from its PPA:
$ sudo add-apt-repository ppa:jonls/redshift-ppa $ sudo apt-get update $ sudo apt install redshift-gtk
Invoke it as Redshift from the Dash or as
redshift at the commandline. You can see its icon appear in the Panel.
By default, it uses the geoclue framework to figure out the latitude-longitude of your location. It automatically adjusts the color temperature of your display for your time of day. So, at night it will change the color temperature of your display to a warm red.
You can toggle Redshift on or off from its Panel icon. When it is on, the bulb in the icon is red, while it is off, the bulb is blue.
You can also suspend it for a certain amount of time (30 min or 1 hour) from the icon in the Panel.
By default, I found that during day Redshift sets a light warm color temperature. And the night color temperature was also too warm for my taste.
All settings of Redshift can be configured by setting them in a
~/.config/redshift.conf file. An example of this file can be found in
/usr/share/doc/redshift/example-redshift.conf. This has example values of all the settings. You can set only those needed, the rest will be picked up from the default values that Redshift uses.
For picking a suitable color temperature, I find the chart available here useful. For example, I found that I like my display to be like LCD during day (which is 6500K). For night, if I have a lamp in the room I pick 3500K and if I am working in complete darkness I pick 2500K.
Tried with: Redshift 1.9.1 and Ubuntu 15.04