ToggleButtons Example

import java.awt.Color;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.GroupLayout;
import static javax.swing.GroupLayout.Alignment.CENTER;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JToggleButton;
import static javax.swing.LayoutStyle.ComponentPlacement.UNRELATED;
import javax.swing.border.LineBorder;

public class ToggleButtonEx extends JFrame
        implements ActionListener {

    private JToggleButton redBtn;
    private JToggleButton greenBtn;
    private JToggleButton blueBtn;
    private JPanel display;

    public ToggleButtonEx() {

        initUI();
    }

    private void initUI() {

        redBtn = new JToggleButton("red");
        redBtn.addActionListener(this);

        greenBtn = new JToggleButton("green");
        greenBtn.addActionListener(this);

        blueBtn = new JToggleButton("blue");
        blueBtn.addActionListener(this);

        display = new JPanel();
        display.setPreferredSize(new Dimension(120, 120));
        display.setBorder(LineBorder.createGrayLineBorder());
        display.setBackground(Color.black);

        createLayout(redBtn, greenBtn, blueBtn, display);
       
        setTitle("JToggleButton");
        setLocationRelativeTo(null);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }

    private void createLayout(JComponent... arg) {
       
        Container pane = getContentPane();
        GroupLayout gl = new GroupLayout(pane);
        pane.setLayout(gl);         
       
        gl.setAutoCreateContainerGaps(true);
        gl.setAutoCreateGaps(true);
       
        gl.setHorizontalGroup(gl.createSequentialGroup()
                .addGroup(gl.createParallelGroup()
                    .addComponent(arg[0])
                    .addComponent(arg[1])
                    .addComponent(arg[2]))
                .addPreferredGap(UNRELATED)
                .addComponent(arg[3])
        );

        gl.setVerticalGroup(gl.createParallelGroup(CENTER)
                .addGroup(gl.createSequentialGroup()
                    .addComponent(arg[0])
                    .addComponent(arg[1])
                    .addComponent(arg[2])) 
                .addComponent(arg[3])
        );       
       
        gl.linkSize(redBtn, greenBtn, blueBtn);

        pack();       
    }

    @Override
    public void actionPerformed(ActionEvent e) {

        Color color = display.getBackground();
        int red = color.getRed();
        int green = color.getGreen();
        int blue = color.getBlue();

        if (e.getActionCommand().equals("red")) {
            if (red == 0) {
                red = 255;
            } else {
                red = 0;
            }
        }

        if (e.getActionCommand().equals("green")) {
            if (green == 0) {
                green = 255;
            } else {
                green = 0;
            }
        }

        if (e.getActionCommand().equals("blue")) {
            if (blue == 0) {
                blue = 255;
            } else {
                blue = 0;
            }
        }

        Color setCol = new Color(red, green, blue);
        display.setBackground(setCol);
    }

    public static void main(String[] args) {

        EventQueue.invokeLater(() -> {
            ToggleButtonEx ex = new ToggleButtonEx();
            ex.setVisible(true);
        });
    }
}