Problem Listener JComboBox

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
 
class EssaiChoix extends JPanel implements ItemListener {
	JComboBox combo1 = new JComboBox();
	JComboBox combo2 = new JComboBox();
	Ardoise ardoise = new Ardoise();
 
	EssaiChoix() {
		JPanel panneau = new JPanel();
		combo1.addItem("noir");
		combo1.addItem("rouge");
		combo1.addItem("vert");
		combo1.addItem("bleu");
		combo1.addItem("jaune");
		combo1.setToolTipText("combo1");
		combo2.addItem("1");
		combo2.addItem("2");
		combo2.addItem("3");
		combo2.addItem("4");
		combo2.addItem("5");
		combo2.setToolTipText("combo2");
		panneau.add(combo1);
		panneau.add(combo2);
		combo1.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				ardoise.setForeground(getCouleur((String) combo1
						.getSelectedItem()));
			}
		});
		combo2.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				combo1.setSelectedIndex(combo2.getSelectedIndex());
			}
		});
		setLayout(new BorderLayout(5, 5));
		add(panneau, BorderLayout.NORTH);
		add(panneau, BorderLayout.EAST);
		add(ardoise, BorderLayout.CENTER);
	}
 
	public void itemStateChanged(ItemEvent evt) {
		ardoise.setForeground(getCouleur((String) combo1.getSelectedItem()));
	}
 
	Color getCouleur(String s) {
		if (s.equals("noir"))
			return Color.black;
		else if (s.equals("rouge"))
			return Color.red;
		else if (s.equals("vert"))
			return Color.green;
		else if (s.equals("bleu"))
			return Color.blue;
		else if (s.equals("jaune"))
			return Color.yellow;
		return Color.black;
	}
 
	public static void main(String[] argv) {
		JFrame monCadre = new JFrame();
		monCadre.setTitle("Ardoise");
		monCadre.setContentPane(new EssaiChoix());
		monCadre.addWindowListener(new WindowAdapter() {
			public void windowClosing(WindowEvent e) {
				System.exit(0);
			}
		});
		monCadre.pack();
		monCadre.setVisible(true);
	}
}
 
class Ardoise extends JPanel {
	Ardoise() {
		setPreferredSize(new Dimension(100, 100));
	}
 
	public void paintComponent(Graphics g) {
		super.paintComponent(g);
		g.fillOval(10, 10, 130, 80);
	}
}