Gnome also has a similar feature now, night light http://www.omgubuntu.co.uk/2017/02/gnome-night-light-blue-light-filter-linux http://www.omgubuntu.co.uk/2017/

Gnome also has a similar feature now, night light http://www.omgubuntu.co.uk/2017/02/gnome-night-light-blue-light-filter-linux http://www.omgubuntu.co.uk/2017/02/gnome-night-light-blue-li...