MANTENER EL COLOR DE UN BOTON CUANDO CAMBIO DE JFRAME

BUENAS NOCHES;

QUIERO MANTENER EL COLOR VERDE DEL BOTON CUANDO CAMBIO DE JFRAME Y LUEGO REGRESO A EL..

EL CODIGO ES.

*******************************************************************************************************************************
JFRAME 1
*******************************************************************************************************************************
import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.JButton;
import java.awt.Color;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

@SuppressWarnings("serial")
public class VENTANA1 extends JFrame {

static int VARIABLE1 = 120;
static int VARIABLE2;

private JPanel contentPane;

/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
VENTANA1 frame = new VENTANA1();
frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}

/**
* Create the frame.
*/
public VENTANA1() {
setTitle("VENTANA1");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 450, 300);
contentPane = new JPanel();
contentPane.setBackground(Color.LIGHT_GRAY);
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
setContentPane(contentPane);
contentPane.setLayout(null);

final JButton btnNewButton = new JButton("ON");
btnNewButton.addMouseListener(new MouseAdapter() {
@Override
public void mouseClicked(MouseEvent arg0) {
btnNewButton.setBackground(Color.GREEN);
}
});
btnNewButton.setBackground(Color.GRAY);
btnNewButton.setBounds(121, 122, 91, 23);
contentPane.add(btnNewButton);

JButton btnNewButton_1 = new JButton("NEXT");
btnNewButton_1.addMouseListener(new MouseAdapter() {
@Override
public void mouseClicked(MouseEvent arg0) {

VENTANA2 nuevaventana = new VENTANA2(); // PARA ABRIR LA NUEVA
// VENTANA
nuevaventana.setVisible(true); // PARA ABRIR LA NUEVA VENTANA
VENTANA1.this.dispose(); // PARA QUITAR LA VENTANA MENU
}
});
btnNewButton_1.setBackground(Color.GRAY);
btnNewButton_1.setBounds(341, 239, 91, 23);
contentPane.add(btnNewButton_1);

JButton btnNewButton_2 = new JButton("OFF");
btnNewButton_2.setBackground(Color.GRAY);
btnNewButton_2.setBounds(243, 122, 91, 23);
contentPane.add(btnNewButton_2);
}

}

************************************************************************************************************************************
JFRAME 2
************************************************************************************************************************************

import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.JButton;
import java.awt.Color;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

@SuppressWarnings("serial")
public class VENTANA2 extends JFrame {

private JPanel contentPane;

/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
VENTANA2 frame = new VENTANA2();
frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}

/**
* Create the frame.
*/
public VENTANA2() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 450, 300);
contentPane = new JPanel();
contentPane.setBackground(Color.LIGHT_GRAY);
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
setContentPane(contentPane);
contentPane.setLayout(null);

JButton btnNewButton_1 = new JButton("ATRAS");
btnNewButton_1.addMouseListener(new MouseAdapter() {
@Override
public void mouseClicked(MouseEvent arg0) {

VENTANA1 nuevaventana = new VENTANA1(); // PARA ABRIR LA NUEVA
// VENTANA
nuevaventana.setVisible(true); // PARA ABRIR LA NUEVA VENTANA
VENTANA2.this.dispose(); // PARA QUITAR LA VENTANA MENU
}
});
btnNewButton_1.setBackground(Color.GRAY);
btnNewButton_1.setBounds(341, 239, 91, 23);
contentPane.add(btnNewButton_1);
}
}