Add color and subcategory styling to category and chat mentions

[pfaffman (Jay Pfaffman)]

@Jagster

And let admins use CSS as it is created… change the look and feel as they want.

Most admins have zero idea that is even possible.

@Canapin

Subcategories may be “sub”, but they are categories by design

Yes. I think you should not treat them differently (and there are also little known sub sub categories).