Hi,
how to make the parent category is visible in the list of categories to add quiz?
(add quiz off, but it is visible)
(subcategory names are related to the parent category - it should be visible but other colour)
Sorry, I didn't see this post. That's not really possible as the parent category is still available to have quizzes added to it. I'll add it as a feature request to make a category not available to have quizzes added to it (so it will work as a parent category only).