I gave a try to 8 U40 b07 to experiment the fix of RT-38395.
I get the NPE below using the small attached app that mimics what SceneBuilder does.
Simply click on any of the two buttons for switching to Modena yellow-on-black.

Exception in thread "JavaFX Application Thread" java.lang.NullPointerException
at com.sun.javafx.css.Declaration.readBinary(Declaration.java:184)
at com.sun.javafx.css.Rule.getUnobservedDeclarationList(Rule.java:79)
at com.sun.javafx.css.Rule$Observables.<init>(Rule.java:276)
at com.sun.javafx.css.Rule$Observables.<init>(Rule.java:246)
at com.sun.javafx.css.Rule.getDeclarations(Rule.java:118)
at com.sun.javafx.css.StyleMap.getCascadingStyles(StyleMap.java:85)
at javafx.scene.CssStyleHelper.getStyle(CssStyleHelper.java:826)
at javafx.scene.CssStyleHelper.lookup(CssStyleHelper.java:882)
at javafx.scene.CssStyleHelper.transitionToState(CssStyleHelper.java:679)
at javafx.scene.Node.impl_processCSS(Node.java:9168)
at javafx.scene.Parent.impl_processCSS(Parent.java:1239)
at javafx.scene.Node.processCSS(Node.java:9035)
at javafx.scene.SubScene.impl_processCSS(SubScene.java:563)
at javafx.scene.Node.processCSS(Node.java:9035)
at javafx.scene.SubScene.processCSS(SubScene.java:573)
at javafx.scene.Node.processCSS(Node.java:9028)
at javafx.scene.Scene.doCSSPass(Scene.java:515)
at javafx.scene.Scene.access$3600(Scene.java:145)
at javafx.scene.Scene$ScenePulseListener.pulse(Scene.java:2353)
at com.sun.javafx.tk.Toolkit.lambda$runPulse$29(Toolkit.java:314)
at com.sun.javafx.tk.Toolkit$$Lambda$149/734868266.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.Toolkit.runPulse(Toolkit.java:313)
at com.sun.javafx.tk.Toolkit.firePulse(Toolkit.java:340)
at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:508)
at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:488)
at com.sun.javafx.tk.quantum.QuantumToolkit.lambda$runToolkit$395(QuantumToolkit.java:315)
at com.sun.javafx.tk.quantum.QuantumToolkit$$Lambda$41/830445879.run(Unknown Source)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)