NullPointerException when trying to render Box with Opacity

Crashes when trying to render a Box set to a PhongMaterial, with a Opacity in the Color Value.
Execute the examplecode , and set the color in the ColorPicker to a opacety value !=1.

Code:

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.ColorPicker;
import javafx.scene.layout.StackPane;
import javafx.scene.paint.PhongMaterial;
import javafx.scene.shape.Box;
import javafx.scene.shape.CullFace;
import javafx.scene.shape.DrawMode;
import javafx.stage.Stage;

public class JavaFXApplication30 extends Application {

    @Override
    public void start(Stage primaryStage) {
        StackPane root = new StackPane();
        Box bounds = new javafx.scene.shape.Box(10 ,10,10);
        PhongMaterial material = new PhongMaterial();
        ColorPicker tmp = new ColorPicker();
        root.getChildren().add(tmp);
        material.diffuseColorProperty().bind(tmp.valueProperty());
        bounds.setMaterial(material);
        bounds.setDrawMode(DrawMode.FILL);
        bounds.setCullFace(CullFace.BACK);

        root.getChildren().add(bounds);

        Scene scene = new Scene(root, 300, 250);

        primaryStage.setTitle("Hello World!");
        primaryStage.setScene(scene);
        primaryStage.show();
    }

}