anchor.diff:      favorite-apps=[ 'org.gnome.Epiphany.desktop', 'org.gnome.Geary.desktop', 'org.gnome.Calendar.desktop', 'org.gnome.Music.desktop', 'org.gnome.Photos.desktop', 'org.gnome.Nautilus.desktop' ]
     '';
   
  +  nixos-background-ligtht = pkgs.nixos-artwork.wallpapers.simple-blue;
  +  nixos-background-dark = pkgs.nixos-artwork.wallpapers.simple-dark-gray;
  +
     nixos-gsettings-desktop-schemas = let
       defaultPackages = with pkgs; [ gsettings-desktop-schemas gnome.gnome-shell ];
     in
  
positive.code:      chmod -R a+w $out/share/gsettings-schemas/nixos-gsettings-overrides
       cat - > $out/share/gsettings-schemas/nixos-gsettings-overrides/glib-2.0/schemas/nixos-defaults.gschema.override <<- EOF
         [org.gnome.desktop.background]
         picture-uri='file://${pkgs.nixos-artwork.wallpapers.simple-blue.gnomeFilePath}'
         picture-uri-dark='file://${pkgs.nixos-artwork.wallpapers.simple-dark-gray.gnomeFilePath}'
  
         [org.gnome.desktop.screensaver]
         picture-uri='file://${pkgs.nixos-artwork.wallpapers.simple-dark-gray-bottom.gnomeFilePath}'
  
         ${cfg.favoriteAppsOverride}
  
  
negative.code:       # Adapt from https://gitlab.gnome.org/GNOME/gnome-build-meta/blob/gnome-3-38/elements/core/meta-gnome-core-shell.bst
        environment.systemPackages = with pkgs.gnome; [
          adwaita-icon-theme
          nixos-background-info
          gnome-backgrounds
          gnome-bluetooth
          gnome-color-manager
  