Java swing repaint() is painting an unrelated panel onto the panel that is being repainted?

Question

I am having a problem with my code where the left menu bar is being duplicated whenever I draw something in my program. When a shape gets created, it repaints the panel but is also painting the left menu bar into the panel, as you can paint over it with a new shape and it gets covered and isn't functional. I'm not sure what is causing this, but the painting panel should also have it's background color set to Cyan which isn't happening.

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

public class Main extends JFrame implements ActionListener {
    DrawPanel centerPanel;
    
    public static void main(String[] args) {
        Main main = new Main();
        main.setSize(500,500);
        main.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        main.setVisible(true);
    }
    
    public Main() {
        super("My Paint App");
        // South
        JPanel southPanel = new JPanel();
        southPanel.setBackground(Color.BLACK);
        JButton b1 = new JButton("Undo");
        JButton b2 = new JButton("Erase");
        southPanel.add(b1);
        southPanel.add(b2);
        // West
        JPanel westPanel = new JPanel();
        westPanel.setBackground(Color.BLACK);
        String[] colors = {"Black", "Red", "Blue", "Green", "Yellow", "Orange", "Pink"};
        JComboBox<String> list = new JComboBox<String>(colors);
        JRadioButton rectangle = new JRadioButton("Rectangle");
        JRadioButton circle = new JRadioButton("Circle");
        JRadioButton arc = new JRadioButton("Arc");
        rectangle.setSelected(true);
        ButtonGroup group = new ButtonGroup();
        group.add(rectangle);
        group.add(circle);
        group.add(arc);
        GridLayout grid = new GridLayout(7,1);
        westPanel.setLayout(grid);
        westPanel.add(list);
        westPanel.add(rectangle);
        westPanel.add(circle);
        westPanel.add(arc);
        // Center
        centerPanel = new DrawPanel();
        centerPanel.setBackground(Color.CYAN);
        // Frame
        BorderLayout layout = new BorderLayout();
        setLayout(layout);
        add(southPanel, BorderLayout.SOUTH);
        add(westPanel, BorderLayout.WEST);
        add(centerPanel, BorderLayout.CENTER);
        // Listeners
        list.addActionListener(this);
        rectangle.addActionListener(this);
        circle.addActionListener(this);
        arc.addActionListener(this);
        b1.addActionListener(this);
        b2.addActionListener(this);
    }
    
    @Override
    public void actionPerformed(ActionEvent e) {
        System.out.println(e.getActionCommand());
        //** If color combo box is changed, updates what color to draw with
        if (e.getActionCommand().equals("comboBoxChanged")) {
            JComboBox tmp = (JComboBox) e.getSource();
            Object selection = tmp.getSelectedItem();
            System.out.println(selection);
            if (selection.equals("Black"))
                centerPanel.setColor(Color.BLACK);
            else if (selection.equals("Red"))
                centerPanel.setColor(Color.RED);
            else if (selection.equals("Blue"))
                centerPanel.setColor(Color.BLUE);
            else if (selection.equals("Green"))
                centerPanel.setColor(Color.GREEN);
            else if (selection.equals("Yellow"))
                centerPanel.setColor(Color.YELLOW);
            else if (selection.equals("Orange"))
                centerPanel.setColor(Color.ORANGE);
            else if (selection.equals("Pink"))
                centerPanel.setColor(Color.PINK);
        }
        //** If shape radio buttons are changed, updates what shape to draw
        if (e.getActionCommand().equals("Rectangle"))
            centerPanel.setShape("rectangle");
        else if (e.getActionCommand().equals("Circle"))
            centerPanel.setShape("circle");
        else if (e.getActionCommand().equals("Arc"))
            centerPanel.setShape("arc");
    }

}

import javax.swing.*;
import java.awt.*;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;

public class DrawPanel extends JPanel implements MouseListener, MouseMotionListener {
    int x1, y1, x2, y2;
    Color color = Color.BLACK;
    String shape = "rectangle";
    
    public DrawPanel() {
        addMouseListener(this);
        addMouseMotionListener(this);
    }
    
    public void paintComponent (Graphics g) {
        g.setColor(color);
        if (shape.equals("rectangle"))
            g.fillRect(x1, y1, x2-x1, y2-y1);
        else if (shape.equals("circle"))
            g.fillOval(x1, y1, x2-x1, y2-y1);
        else if (shape.equals("arc"))
            g.fillArc(x1, y1, y2, y1, x2, x1);
    }
    
    public void mousePressed(MouseEvent e) {
        x1 = e.getX();
        y1 = e.getY();
    }
    
    public void mouseReleased(MouseEvent e) {
        x2 = e.getX();
        y2 = e.getY();
        System.out.println(x1 + ", " + y1 + ", " + x2 + ", " + y2);
        repaint();
    }
    
    public void setColor(Color color) {
        this.color = color;
    }
    
    public void setShape(String shape) {
        this.shape = shape;
    }
    
    public void mouseClicked(MouseEvent e) {}
    public void mouseEntered(MouseEvent e) {}
    public void mouseExited(MouseEvent e) {}
    public void mouseDragged(MouseEvent e) {}
    public void mouseMoved(MouseEvent e) {}
}