Top 3 Best Night Light Apps on Linux

Top 3 Best Night Light Apps on Linux 1

It is very important to understand that a customizable color filter is very important on a monitor. Especially when it comes to daily use and work with a computer. The strain on the eyes sometimes causes some discomfort. This article, which will be presented for your reference, will describe all the advantages of some Night Light applications.

These, in turn, will help you set up and use a properly adjustable color filter on your monitor screen. The important thing to understand is to be able to adjust the color temperature for your display and choose warmer colors. This will undoubtedly help to reduce the amount of light on the eyes, according to the fact that blue filtering will take place. The applications that will be described in this article have one common name “Night Light“.

RedShift – Night Light

RedShift is a custom open source command line with graphical software. This tool is used to change the screen temperature by applying a software filter to your display. Its main advantage is that this tool allows you to automatically change colors depending on what time of day it is at the moment. Mostly at dusk and dawn (depending on your current location) Redshift evenly switches the color temperature of the computer display between day and night temperatures so that the user’s eyes can slowly adapt. At night, the color temperature is low and is usually 3000–4000 K, which preferably corresponds to the lighting temperature in the room. Typical daytime color temperatures are 5500–6500 K.

Redshift adjusts the color temperature of the screen based on your environment. This can reduce eye pain if you work in front of the screen at night. More details about installation and how to use this Night Light tool can be found here

Redshift can be opened using your terminal, launchers, or launch commands. This can be done with the command

  • redshift -O #TEMP

(#TEMP is a number between 1000 and 25000). This command will set the temperature, and the command ‘

  • redshift -x

‘ to exit Redshift. You can create a simple script and call it to manually set the color temperature using a shortcut or launcher. Create a new file and copy the following:

while $shouldloop; do
    read -p "What temp would you like? 1000-25000K: " scale
if "$scale" -ge 1000 && "$scale" -le 25000; then
    redshift -O $scale
elif $scale = "x"; then
elif $scale = "X"; then
    echo "Invalid value or outside range. x to exit..."

To install Redshift Night Light on your server you can use the packages provided by your distribution, for example, for Ubuntu: apt-get install redshift or apt-get install redshift-gtk.

GNOME Shell Night Light

The Blue color has a very negative effect on the perception of the display from the monitor. This inherently can lead to overexertion of your voice and, consequently, sleep disturbance. These factors definitely have a negative impact on your health. This utility – GNOME Shell Night Light – contains a special night light option. This can be manually configured and included in your system settings. If you are running any GNOME Shell-based Linux distribution that has received a new version of GNOME Shell in the last couple of years, your Linux distribution should have built-in nightlight functionality.

The GNOME Shell Night Light has all the features you’d expect from a screen filter app. You can use it to set your desired color temperature and then either manually activate the overlay or schedule it. Its scheduling feature allows you to select an individual time frame or you can schedule it to automatically activate during sunrise and sunset based on your current location.

One of the clear benefits of using GNOME Shell Night Light is that you can manually set the color “temperature” that GNOMENightLight sets for your monitor. If you’ve ever used an LED light bulb, you should be familiar with the concept of color temperature. Lower temperatures are usually warmer and redder in color. Higher temperatures are found in the blue or red spectrum. The goal here is to move the monitor to a lower, redder temperature.

Top 3 Best Night Light Apps on Linux 2

It is very easy to enable GNOME Shell. In order to enable GNOMEShell you need to go to your GNOME settings in the upper right corner, then click the “Displays” icon. At the top of the pop-up window, click the Night Light submenu.

Top 3 Best Night Light Apps on Linux 3

Set Color Temperature (SCT)

SCT is a unique free command line utility. It is open source, allowing you to change the color temperature of your display using a program. This utility is not entirely common, and that is why it is described in this article. Its essence is very simple – it represents just one command that accepts the desired color temperature as a numerical value. More details are presented here

It is also described that the redshift mechanism used to change the color temperature is XRandR. It is a special protocol for resizing and rotating along the X-axis. There is even an official configuration utility, xrandr. There is a gamma option! But for this purpose, it is practically unsuitable. If you set the RGB gamma to 1.0: 0.9: 0.4, the screen will not become “warm”. The gray turns into ugly vomit, while the white remains as bright and cold as before. I don’t just want to bend the gamma curve, I want to compress or crop it so that there is no blue = 255px.

It actually only takes about 40 C lines to set the screen color temperature (80 or so all included). sct is a crude utility that does much the same thing. I would say that, but some of the calculations are actually inaccurate. In any case, it looks much, much better than anything xrandr can provide. Accepts temperature values ​​in the range from 1000 to 10000.

Installing SCT Night Light

An example will be shown for a Linux distribution such as Ubuntu. In order to install SCT Night Light on your server, please use the following command:

apt install sct

SCT is available in the official repositories of all major distributions. You can also get executable binaries by compiling the source code available on its GitHub page. If, for example, you need to set a fixed color temperature, use the following command:

sct 1000 

You can replace 1000 with whatever you want.

In order to remove the changes that you made with the SCT, you need to enter the following:


This command will also allow you to reset all previous SCT settings.

In order for you to be able to get additional information about the parameters you need, you must do the following:

$man sct
sct -h