How to use

NimbusLookAndFeel

in

javax.swing.plaf.nimbus

  private static void openMainForm(String title, Parameters parameters) {
    try {
      UIManager.setLookAndFeel(new NimbusLookAndFeel());
    } catch (UnsupportedLookAndFeelException e) {
      throw new RuntimeException(e);
    }

    MainFrame form = new MainFrame(title, parameters);
    form.pack();
    form.setLocationRelativeTo(null);
    form.setVisible(true);
  }
}

@Override
public UIDefaults getDefaults()
{
 UIDefaults defaults = super.getDefaults();
 GraphicsDevice gd = GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice();
 if(gd.getDisplayMode().getWidth() > 2000)
 {
  defaults.put("defaultFont", new Font(Font.SANS_SERIF, Font.PLAIN, 18));
 }
 return defaults;
}

 @Override
 public void provideErrorFeedback(Component component) {
  if (Configurations.currentConfiguration.getSound().isAlertSound()) {
   super.provideErrorFeedback(component);
  }
 }
});

  UIManager.setLookAndFeel(new javax.swing.plaf.nimbus.NimbusLookAndFeel());
} catch (UnsupportedLookAndFeelException e) {

protected static Dimension arcs = new Dimension(10, 10);
public TabbedPaneTheme(NimbusBaseUI nimbusUI) {
 UIDefaults d = nimbusUI.getDefaults();

  UIManager.setLookAndFeel(new NimbusLookAndFeel());
} catch (UnsupportedLookAndFeelException e) {
  e.printStackTrace();

  UIManager.setLookAndFeel(new NimbusLookAndFeel());
} catch (UnsupportedLookAndFeelException e) {
  e.printStackTrace();