You can also force Nimbus to be the default look and feel by specifying -Dswing.defaultlaf=com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel. on the command line.

So I'm just trying to figure out how to make this happen when I run the program within Netbeans. As far as I can tell all the look and feel options are set to use the system default.