Simple, simple questoin on FOW

Yes, fog of war...Ya know, that black stuff that cover's the map?

Well, here's the thing. How do you put it in? Currently I've got some opaque grey that you can see through, and that let's you see the minimap. How do I make a black one?

Thanks for your time.

I think what your looking for is:

Visibility - Enable black mask

or

Visibility - Enable Fog of War