as I saw, the text for e.g. the yesno pop-up is rendered in a textpane. Would it be possible to define an own style variant for popups?
In my case I want in popups a transparent background, but in my pages a white one?
...yes, here we can do this becaus TEXTPANE default style is not defined at all so far - and in the popup we clearly want to have a transparent text pane.
In other situations we would normally do it vice versa: define a style variant for text pane on your own, and refer to this style variant in the component definition.