*/
  public void color_mask (boolean red, boolean green, boolean blue,
                          boolean alpha) {

    RequestOutputStream o = display.out;
    synchronized (o) {
      begin_render_request (o, 134, 8);
      o.write_bool (red);
      o.write_bool (green);
      o.write_bool (blue);
      o.write_bool (alpha);
    }
  }