When posts/ and threads/ do, editor/dialog doesn't get its style overridden if the parent node has the "Override user style choice" option set to a different than the default style. Reproduce: Edit a Node and set the "Override user style choice" to a random style. Make sure it has different color variations from the default one. Start editing a post in any of its threads. Style inheritance has worked well till now. Click on any Dialog triggering button in your WYSIWYG. Dialog opens with the default style, without respecting the parent one. If the request to editor/dialog had the thread_id (or even better the post_id) parameter, it would be easy to determine the style of the parent node.