xrandr

This post is obsolete. Please check the new manual at this post

Install driver

Add negativo17's repo

$ sudo dnf config-manager --add-repo=https://negativo17.org/repos/fedora-nvidia.repo

Install NVIDIA driver

$ sudo dnf install nvidia-driver nvidia-driver-libs.i686

Create a script file night_mode

#!/bin/sh

night_mode() {
    xrandr --output VGA-1 --gamma $1 --brightness $2
}
case $1 in
  off) night_mode 1:1:1 1.0 ;;
  *) night_mode 1:0.85:0.6 1.0 ;;
esac