Unable to color circle buttons

Hello,

I tried to use CircleButton instead of JButton. It works fine except when I want to color these buttons. Maybe there is something I have missed ?
Below if my code. As you can seen my original JButton are colored in green and red. However I have no color when changing JButton by CircleButton.
Thanks
Gerard

import java.awt.Color;
import javax.swing.JEditorPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;

import javax.swing.JButton;

public class OuiNon extends javax.swing.JDialog 
{
	/*--------------------------------------------------------------------------------------------------------*/
	/*                           Variables et constantes 													  */
	/*--------------------------------------------------------------------------------------------------------*/
	
	private static final long 	serialVersionUID	= 6525398796677379148L;
	private JButton 			Non 				= null,
	   			                        Oui	 				= null;
	private JPanel 				monPanneau 			= null;
	private JEditorPane			montexte 			= null;
	public boolean 				reponse				= false;
	private JScrollPane 		scroll				= null;
	
	/*---------------------------Fin des déclaratives-----------------------------------------------è---------*/
	
 
	public OuiNon() 
	{
		super();
		créerBoites();
	}

	public OuiNon(java.awt.Frame owner, String msg, boolean modal) 
	{
		super(owner,"Répondre par Oui ou Non", modal);
		initialize(msg);
	}

 	private void créerBoites()
 	{
 		 		setName("YesNo");
		setDefaultCloseOperation(javax.swing.WindowConstants.DISPOSE_ON_CLOSE);
		setSize(503, 357);
	  
		montexte = new JEditorPane();
			montexte.setName("montexte");
			montexte.setText(" ");
			montexte.setBounds(11, 5, 462, 220);
			montexte.setContentType("text/html");
			
		scroll  = new JScrollPane(montexte);
			scroll.setBounds(11, 5, 462, 220);	
			
		Non = new JButton("");
		  	Non.setName("ExecNon");
			Non.setText("Non");
			Non.setOpaque(true);
			Non.setBackground(new  Color(255,0,0));
			Non.setBounds(337, 256, 89, 23);
			Non.addActionListener(e -> { reponse = false;setVisible(false);});
		
			
		Oui = new JButton("");
			Oui.setName("ExecOui");
			Oui.setText("Oui");
			Oui.setOpaque(true);
			Oui.setBackground(new java.awt.Color(0,255,0));
			Oui.setBounds(67, 256, 89, 23);
			Oui.addActionListener(e -> { reponse = true;setVisible(false);});
			
		monPanneau = new JPanel();
		monPanneau.setName("monPanneau");
		monPanneau.setLayout(null);	
		monPanneau.add(Oui);
		monPanneau.add(Non);
		monPanneau.add(scroll); 
		
		setContentPane(monPanneau ); 
		this.setLocationRelativeTo (null);
 	}
 	
 	private void initialize(String msg) 
 	{
 		créerBoites();
 		if (! msg.startsWith("<html>"))
 		{
 			montexte.setText("<html><font size=-1 color=black><b>" + msg + "</b></font></html>");
 		}
 		else
 		{
 			montexte.setText(  msg);
 		}
	    setVisible(true);
 	}

 	public static void main(java.lang.String[] args) 
 	{
		 new OuiNon(null,"Ceci est mon texte", false);
	}
}

I resolved my problem by overriding setBackground(), setForeground(), setOpaque(), et some other methods in the CircleButton class.