Switching SB theme to "Dark theme", I've seen the following missing styling:

- "?" icon is difficult to see (#D nodes, custom component, ...) - will be dealt with as part of DTL-6396

- Messages in the message bar are difficult to read - fixed in changeset 29984f46b073

- Inspector: all popups :
     text is difficult to read. Seems like disabled items for a ChoiceBox.
     background should be darker (Font, Color, Effect editors)
- Inspector: the focus rings are not visible. This is annoying for key navigation. - fixed in changeset 29984f46b073

- Inspector: the cog icon is difficult to see. Once clicked, too much contrast. - fixed in changeset 3d47cc7fe7c1

- TableView is not taken care of in the theme. This impacts:
      CSS Analyzer
      Controller Section - fixed in changeset 47f922afd8e8

When an fxml with a Dark theme is opened, the following Warning appears: - fixed in changeset 29984f46b073
WARNING: Could not resolve '-sb-control-inner' while resolving lookups for '-fx-background-color' from rule '*.panel-header *.text-field:focused' in stylesheet file:/C:/wksfx/sb20/SceneBuilderApp/build/classes/com/oracle/javafx/scenebuilder/app/css/DocumentWindow.css