Couldn’t resist drafting something.
Orange color would point to pages with elements not in sync (text elements that remain unedited after language duplicate page).
You would have the option to let a page in full sync (only being able to edit text blocks and images) and to break the sync to add custom content for language specific page. If you could manage both the sync and custom content working at the same time I’d praise your skills all over the web. (I’m kidding, I already do that).
Thanks for listening!