Change color on focus

Hello everyone out there, another question.

I realized I need to ask you questions so you have them to answer!


How can I get the Jpanels color to get set on focus

 

   
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class BlocksAndHandStricks extends JPanel
{ // Opens class

    JPanel jPanel1;
    JPanel jPanel1A;
    JPanel jPanel1B;
    JPanel jPanel1C;
    JPanel jPanel2;
    JPanel jPanel2A;
    JPanel jPanel2B;
    JPanel jPanel2C;
    JPanel jPanel3;
    JPanel jPanel4;

    JLabel jLabel1;
    JLabel jLabel2;
    JLabel jLabel3;
    JLabel jLabel4;
    JLabel jLabel5;
    JLabel jLabel6;
    JLabel jLabel7;
    JLabel jLabel8;
    JLabel jLabel9;
    JLabel jLabel10;
    JLabel jLabel11;
    JLabel jLabel12;
   

    public BlocksAndHandStricks()
    {
        super();

Font f1 = new Font("Courier New", Font.BOLD, 15);

jPanel1 = new javax.swing.JPanel();
jPanel1A = new javax.swing.JPanel();
jPanel1B = new javax.swing.JPanel();


jLabel1 = new javax.swing.JLabel();
jLabel2 = new javax.swing.JLabel();
jLabel3 = new javax.swing.JLabel();
jPanel2 = new javax.swing.JPanel();
jPanel2A = new javax.swing.JPanel();
jPanel2B = new javax.swing.JPanel();
jPanel2C = new javax.swing.JPanel();
jLabel4 = new javax.swing.JLabel();
jLabel5 = new javax.swing.JLabel();
jLabel6 = new javax.swing.JLabel();
jPanel3 = new javax.swing.JPanel();
jLabel7 = new javax.swing.JLabel();
jLabel8 = new javax.swing.JLabel();
jLabel9 = new javax.swing.JLabel();
jPanel4 = new javax.swing.JPanel();
jLabel10 = new javax.swing.JLabel();
jLabel11 = new javax.swing.JLabel();
jLabel12 = new javax.swing.JLabel();

setLayout(new java.awt.FlowLayout(java.awt.FlowLayout.LEFT));

jPanel1.setLayout(new javax.swing.BoxLayout(jPanel1, javax.swing.BoxLayout.Y_AXIS));
jPanel1.add(Box.createGlue());

add(jPanel1);
jPanel1.add(jPanel1A);
jPanel1.add(jPanel1B);
jPanel1A.setBorder(BorderFactory.createLoweredBevelBorder());
jPanel1B.setBorder(BorderFactory.createRaisedBevelBorder());


jPanel1A.add(new MyClass4());
jPanel1A.setBackground(Color.white);
jPanel1B.add(new MyClass4());
jPanel1B.setBackground(Color.yellow);


add(jPanel2);
jPanel2.add(Box.createGlue());
jPanel2.setLayout(new javax.swing.BoxLayout(jPanel2, javax.swing.BoxLayout.Y_AXIS));
jPanel2.setBorder(BorderFactory.createLoweredBevelBorder());

jPanel2.add(jLabel4);


jPanel2.add(jLabel5);

jLabel6.setText("jLabel6");
jPanel2.add(jLabel6);



jPanel3.setLayout(new javax.swing.BoxLayout(jPanel3, javax.swing.BoxLayout.Y_AXIS));


jLabel8.setText("jLabel8");
jPanel3.add(jLabel8);

jLabel9.setText("jLabel9");
jPanel3.add(jLabel9);

add(jPanel3);

jPanel4.setLayout(new javax.swing.BoxLayout(jPanel4, javax.swing.BoxLayout.Y_AXIS));

jLabel10.setText("jLabel10");
jPanel4.add(jLabel10);

jLabel11.setText("jLabel11");
jPanel4.add(jLabel11);

jLabel12.setText("jLabel12");
jPanel4.add(jLabel12);

add(jPanel4);

  }
}

This is called from above class


import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;

public class MyClass4 extends JPanel {
  JLabel jLabel1;  
 
  ArrayList myArrayList = new ArrayList();

// Constructor
public MyClass4() {

    setLayout(new GridLayout(0,3)); // Setting MY layout...

add(jLabel1);  jLabel1.setText("Defensive Moves"); setBackground(Color.white);

    looprow:
        for (int row=0; row<20; row++) {
            for(int col=0; col<3; col++) {
                int n=(20*col+row+1);
                if (n>50) break looprow;
                JCheckBox check = new JCheckBox("" + n);

            myArrayList.add(check);
add(check); // Adding it to ME
}
}
}
}