Night-light feature is enabled also in GDM screen, see
here : https://bugzilla.gnome.org/show_bug.cgi?id=785273
for more info.
If you want to disable it please type this command:
运行命令
sudo -u gdm dbus-launch --exit-with-session gsettings set org.gnome.settings-daemon.plugins.color night-light-enabled false