Users wouldn't want to use styleClass to change to the style of the background. In general the styleClass should only be rendered on the root element of the main visual structure of a component. Are you rendering the 'style' attribute on both elements too? What do you think would happen if they used a styleClass and set the padding? The way it is now, that would affect the background overlay too, and be an unintended consequence. If the user ever wants to customize the background overlay they should override the built-in style class for that. And the class for the bg overlay should be the same CSS class for all of our components.
retested, and still an issue