Nimbus and custom painters for a JSpinner

I'm using Nimbus L&F for a project. While I generally like the look of everything, I would like to make the visual cues that a JSpinner has focus a little more apparent. I'm trying to add a custom painter to a spinner with no luck. I'm hoping someone can give me some insight here. Here's what I've done so far:

UIDefaults defSpinner = new UIDefaults();

defSpinner.put( "Spinner:Panel:\"Spinner.formattedTextField\"[Enabled].backgroundPainter", new PainterSpinnerBackgroundEnabled() );

defSpinner.put( "Spinner:Panel:\"Spinner.formattedTextField\"[Focused].backgroundPainter", new PainterSpinnerBackgroundFocused() );

defSpinner.put( "Spinner:Panel:\"Spinner.formattedTextField\"[Focused+Selected].backgroundPainter", new PainterSpinnerBackgroundFocused() );

defSpinner.put( "Spinner:Panel:\"Spinner.formattedTextField\"[Selected].backgroundPainter", new PainterButtonBackgroundFocused() );

spn.putClientProperty( "Nimbus.Overrides", defSpinner );

spn.putclientProperty( "Nimbus.Overrides.InheritDefaults", false );