JPanel colour not changing

[jinnejeevansai]

I was writing a code to change the colour of frame continuously but it is not happening,Can someone point the mistake in my code.

import java.awt.*;
import javax.swing.*;
class cr{
        Color c[] = { Color.BLUE , Color.GREEN , Color.RED };
        int i=0;
        public void design()
        {
                JFrame f = new JFrame();
                f.setSize(200,200);
                f.setVisible(true);
                f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                DrawPanel p = new DrawPanel();
                f.add(p);
                while(true)
                {
                        p.repaint();
                        try
                        {
                                Thread.sleep(5);
                                i++;
                        }
                        catch(Exception e)
                        {
                                System.out.println("error");
                        }
                }
        }
        public class DrawPanel extends JPanel{
                public void PaintComponent(Graphics g)
                {
                        g.setColor(c[i%3]);
                        g.fillRect(0,0,this.getWidth(),this.getHeight());
                }
        }
        public static void main(String args[])
        {
                cr c = new cr();
                c.design();
        }
}