JFX 6.1

package showcircle;

import javafx.scene.paint.Color;
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.layout.Pane;
import javafx.scene.shape.Circle;
import javafx.stage.Stage;


/**
 *
 * @author Monty
 */
public class ShowCircle extends Application{
 @Override
    public void start(Stage stage1){
    Pane pane = new Pane();
    Circle circle = new Circle();
    circle.centerXProperty().bind(pane.widthProperty().divide(2));
    circle.centerYProperty().bind(pane.heightProperty().divide(2));
    circle.setRadius(50);
    circle.setStroke(Color.BLACK);
   Color color = new Color(1,0.1,0.1,0.5);
    circle.setFill(color);
    pane.getChildren().add (circle);
    Scene scene = new Scene(pane, 200, 200);
    stage1.setTitle("MyJavaFX");
    stage1.setScene(scene);
    stage1.show();
    }

    public static void main(String[] args) {
        launch(args);
    }

}