Java Code:
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import java.awt.geom.Rectangle2D;

import javax.swing.JFrame;
import javax.swing.JPanel;

public class XORRectangles extends JPanel{

  public void paint(Graphics g) {
    Graphics2D g2 = (Graphics2D) g;

    // using white as the XOR color.
    g2.setXORMode(Color.white);
    // Paint a red rectangle.
    Rectangle2D r = new Rectangle2D.Double(50, 50, 150, 100);
    g2.setPaint(Color.red);
    g2.fill(r);
    g2.transform(AffineTransform.getTranslateInstance(25, 25));
    // Draw a blue rectangle.
    g2.setPaint(Color.blue);
    g2.fill(r);
  }
  public static void main(String[] args) {
    JFrame f = new JFrame();
    f.getContentPane().add(new XORRectangles());
    f.setSize(300, 200);
    f.setVisible(true);
  }
}