public void actionPerformed(ActionEvent event) {
                if (buttonCount == 1) {
                    buttonCount = 2;
                    Red = Color.red;
                    Yellow = Color.black;
                    Green = Color.black;
                    revalidate();
                    repaint();
                } else if (buttonCount == 2) {
                    buttonCount = 0;
                    Yellow = Color.black;
                    Red = Color.black;
                    Green = Color.green;
                    revalidate();
                    repaint();
                } else if (buttonCount == 0) {
                    buttonCount = 1;
                    Green = Color.black;
                    Red = Color.black;
                    Yellow = Color.yellow;
                    revalidate();
                    repaint();
                }                                                              
            }