[source lang = "java"]

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

public class Main extends JFrame
{
    private Insets limit; // used to determine window boundries 
    private Container c; // used to display stuff
    private Color happyRect;
    
    public Main()
    {
        super("Color Test");
        
        c = getContentPane();
       
        setSize(300,300);
        c.setBackground(Color.blue);
        setVisible(true);
    }
    
    public void paint(Graphics g)
    {
        limit = c.getInsets();
        
        g.setColor(Color.orange);
        g.fillRect(10 + limit.left, 10 + limit.top, 30, 30);
    }
    
    public static void main(String args[])
    {
        Main app = new Main();
        
        app.addWindowListener( new WindowAdapter()
        {
            public void windowClosing(WindowEvent e)
            {
                System.exit(0);
            }
        });
    }
}