Night light mode has been around sometime in smartphone and tablets. It has entered into some Linux distros as a default enabled feature. GNOME desktop environment have added the Night light mode from GNOME 3.24 which got released around a year before.
Now that Ubuntu 17.10 carries GNOME as the default desktop environment, your Ubuntu installation also should have Night light mode built-in, except it doesn’t come enabled by default settings. You have to manually turn it on.
What is Night Light Mode?
In a nutshell, Night light mode lessens strain on your eyes while viewing the computer at night or in the dark. The computer’s display will dim brightness and also screen’s blue color. Blue light is know to cause sleep hormones imbalance in our body which implies harder to fall asleep. With the night light mode, your screen will look red or amber, which has been proven to help your eyes adjust to night vision more smoothly.
Activating Night Light Mode in Ubuntu 17.10
Step 1) Go to ‘Activities’ and launch ‘Settings’ app.
Step 2) Click ‘Devices’ and then ‘Displays’ in the left pane.
Step 3) Click ‘Night Light’.
Step 4) Move the toggle switch to ‘ON’ position. By default settings the night light mode will turn ON when you use your PC between Sunset and Sunrise based on your Ubuntu’s clock time. Optionally, you can enter manual time if needed.
During the mode, you can quickly access/turn off or manage the settings via Control Center.