Bom dia!
Estava procurando um Look and Feel e achei o Substance, que na verdade é um pacote com vários LaFs diferentes.
Encontrei nesse site: http://insubstantial.posterous.com/ e baixei nesse link: https://github.com/Insubstantial/insubstantial/downloads
Descompactei o zip, fui no NetBeans e adicionei todos os .jar em uma Biblioteca chamada Substance, e por fim importei no meu projeto.
s/s da biblioteca e do import:

s/s da chamado do método que define o LaF:

Mensagem de erro:
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at org.pushingpixels.substance.internal.utils.SubstanceColorUtilities.getDefaultBackgroundColor(SubstanceColorUtilities.java:758)
at org.pushingpixels.substance.internal.utils.SubstanceColorUtilities.getBackgroundFillColor(SubstanceColorUtilities.java:661)
at org.pushingpixels.substance.internal.ui.SubstancePanelUI.__org__pushingpixels__substance__internal__ui__SubstancePanelUI__installDefaults(SubstancePanelUI.java:73)
at org.pushingpixels.substance.internal.ui.SubstancePanelUI.installDefaults(SubstancePanelUI.java)
at javax.swing.plaf.basic.BasicPanelUI.installUI(BasicPanelUI.java:56)
at org.pushingpixels.substance.internal.ui.SubstancePanelUI.__org__pushingpixels__substance__internal__ui__SubstancePanelUI__installUI(SubstancePanelUI.java)
at org.pushingpixels.substance.internal.ui.SubstancePanelUI.installUI(SubstancePanelUI.java)
at javax.swing.JComponent.setUI(JComponent.java:664)
at javax.swing.JPanel.setUI(JPanel.java:153)
at javax.swing.JPanel.updateUI(JPanel.java:126)
at javax.swing.JPanel.<init>(JPanel.java:86)
at javax.swing.JPanel.<init>(JPanel.java:109)
at javax.swing.JPanel.<init>(JPanel.java:117)
at javax.swing.JRootPane.createGlassPane(JRootPane.java:545)
at javax.swing.JRootPane.<init>(JRootPane.java:365)
at javax.swing.JFrame.createRootPane(JFrame.java:277)
at javax.swing.JFrame.frameInit(JFrame.java:258)
at javax.swing.JFrame.<init>(JFrame.java:181)
at JOB_Teste.Grafica.<init>(Grafica.java:21)
at JOB_Teste.Grafica$2.run(Grafica.java:87)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:705)
at java.awt.EventQueue.access$000(EventQueue.java:101)
at java.awt.EventQueue$3.run(EventQueue.java:666)
at java.awt.EventQueue$3.run(EventQueue.java:664)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:675)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:211)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:128)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:117)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:113)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:90)
Procurei alguns tutoriais, o processo acima fiz seguindo o tutorial desse topic do proprio guj, porém ignorando a parte da instalação no NetBeans, pois queria testar o LaF antes de alterar o skin da IDE. Alguem de idéia do que possa estar acontecendo?
Obrigado e boa sexta-feira 