How to turn on Night Light Blue Light filter in Ubuntu 20.04

The Night Light filter, also known as Blue Light filter or Color Temperature filter, is a bit hard to find in Ubuntu 20.04. The Night Light tab is now in shown in the title bar, next to the Displays tab. These 2 tab labels look like they are just a title, but in fact they can be clicked on. (BTW it's Settings -> Devices -> Displays: Night Light in Ubuntu 18.04.)

Solution 1:

The Night Light filter, also known as Blue Light filter or Color Temperature filter, is a bit hard to find in Ubuntu 20.04. It's found here:

• Open the Show Applications by clicking on the 9 dots in the lower left of the screen.
• In the 'type to search' textbox (top of screen), type 'Settings'; click on the Settings icon to open the Settings app.
• In the Settings window, choose Displays in the left-side list of setting topics.
• In the title bar at the very top of the window, choose the Night Light tab.
• Turn on the Night Light / blue light filter using the on/off slider.

You can either use the built-in automatic schedule or switch to Manual Schedule using the combobox labeled 'Schedule'. Set the times and the color temp to your preferences. (I set the times as 00:00 to 23:59 so the filter is on all the time.

Solution 2:

For CLI lovers like me, you can also do it using gsetting:

To enable:

gsettings set org.gnome.settings-daemon.plugins.color night-light-enabled true

To disable:

gsettings set org.gnome.settings-daemon.plugins.color night-light-enabled false

With gsettings, you'll be able to make a custom script to just turn it on or off without worrying about the time schedule like so:

To set the starting hour :

gsettings set org.gnome.settings-daemon.plugins.color night-light-schedule-from 12.0

To set the ending hour :

gsettings set org.gnome.settings-daemon.plugins.color night-light-schedule-to 11.9

Here I chose 11.9 as ending and 12.0 as beginning to have it active all day long when it is enabled.

Hope it helps!