//---------------------
        // COMPILE WITH: valac --pkg clutter-gtk-1.0 --pkg gtk+-3.0 test.vala
        //---------------------
        // Problem: The whole window should be red!
        //-------

public static int main (string[] args) {
    Gtk.init (ref args);
        GtkClutter.init (ref args);

    Gtk.Settings.get_default().gtk_application_prefer_dark_theme = true;

    Gtk.Window window;
    GtkClutter.Embed embed;
    Clutter.Stage stage;
    Gdk.RGBA color = {1.0, 0.0, 0.0, 0.5}; /* 50% opaque red */
        //Gdk.RGBA transparent = {0.0, 1.0, 0.0, 0.0}; /* 100% transparent green */
        Clutter.Color c_color = {0, 0, 255, 0}; /* 100% transparent blue*/

        window = new Gtk.Window();

        Gdk.Visual? visu = window.screen.get_rgba_visual();
        if(visu != null) {
            stdout.printf("VISU OK\n");
            window.set_visual(visu);
        } else {
            stdout.printf("VISU NOK\n");
        }

        embed = new GtkClutter.Embed();
        embed.margin_top = 50;

        stage = embed.get_stage () as Clutter.Stage;
        stage.use_alpha = true;
        stage.background_color = c_color;

        window.override_background_color(Gtk.StateFlags.NORMAL, color);
        //embed.override_background_color(Gtk.StateFlags.NORMAL, transparent);

        window.add(embed);
        window.set_default_size (250, 250);


        window.show_all();

        Gtk.main ();
        return 0;
    }
}