If the user chooses to use the gnome default font
        configuration it means that he will not be able to use the
        font selector.

def toggle_use_font_background_sensitivity(self, chk):
        """If the user chooses to use the gnome default font
        configuration it means that he will not be able to use the
        font selector.
        """
        self.get_widget('palette_16').set_sensitive(chk.get_active())
        self.get_widget('palette_17').set_sensitive(chk.get_active())