aqui esta el codigo que hice
Código:
package javaapplication1;
import org.jvnet.substance.SubstanceLookAndFeel;
public class JavaApplication1 {
public static void main(String[] args) {
principal.setDefaultLookAndFeelDecorated(true);
SubstanceLookAndFeel.setSkin("org.jvnet.substance.skin.CremeSkin");
principal p= new principal();
p.setVisible(true);
}