I am not sure if this is a bug.
I transcribed all of this article. http://docs.oracle.com/javafx/2/visual_effects/jfxpub-visual_effects.htm
The result that I saw was different from what I saw in above web site.
The code is here

public class BlendSample extends Application {
    @Override
    public void start(Stage stage) throws Exception {
        HBox root = new HBox();
        root.setPadding(new Insets(10));
        root.setSpacing(8);
        // Blending
        Node node1 = getBlendMode(BlendMode.MULTIPLY, Color.BLUE);
        Node node2 = getBlendMode(BlendMode.SRC_ATOP, Color.ORANGE); // This has the different result
        Node node3 = getBlendMode(BlendMode.SRC_OVER, Color.AQUA);
        root.getChildren().addAll(node1, node2, node3);
        stage.setScene(new Scene(root, 500, 300));
        stage.show();
    }

    static Node getBlendMode(BlendMode mode, Color color) {
        Rectangle r = new Rectangle();
        r.setX(590);
        r.setY(50);
        r.setWidth(50);
        r.setHeight(50);
        r.setFill(color);

        Circle c = new Circle();
        c.setFill(Color.rgb(255, 0, 0, 0.5f));
        c.setCenterX(590);
        c.setCenterY(50);
        c.setRadius(25);

        Group g = new Group();
        g.setBlendMode(mode);
        g.getChildren().add(r);
        g.getChildren().add(c);
        return g;
    }


For your reference please see my blog
http://d.hatena.ne.jp/tomoTaka/20130119/1358580757
Thank you in advance for your help.