If I add a style for .custom-color-dialog to a user-agent stylesheet, the style has no effect. Only if the style is added to a user-agent stylesheet (i.e., Application.setUserAgentStylesheet("blah")) do the styles have any affect. Even scene.setUserAgentStylesheet has no effect.

The issue is that CSS looks for styles by going from a node to node.getStyleableParent() and CustomColorDialog does not return the correct value for getStyleableParent()