gconf_setup() {
  KEY="$1"
  VALUE="$2"
  chroot . gconftool-2 \
    --config-source xml:readwrite:/etc/gconf/gconf.xml.defaults \
    --direct --type string --set $KEY $VALUE \
    1>/dev/null
}

gconf_setup /desktop/gnome/background/picture_filename \
  /usr/share/pixmaps/backgrounds/gnome/gware/gware.png
gconf_setup /desktop/gnome/background/picture_options  centered
gconf_setup /desktop/gnome/background/primary_color    "#1166aa"
gconf_setup /desktop/gnome/background/secondary_color  "#76848f"