Covers, Cap, Service. With visor?

Found this top-left one at the in a cheap-stuff-pile a while back but I don't know a thing about it, I could only find some pics on google of it over a service cap, but it didn't have it's own visor.
Is this some other type or something?

I assume that it's the khaki one in the above left corner?
Did you sew that visor on?
I cannot see the whole cap well, but I think it might be the cover of a cover for the nice dress.
(sorry, I'm not aware of all the correct names of all those tenue's)
What is commonly done in the US forces, they issue you one of a "officers cap" let's say in black for the Navy, when you go then to a tropical area, they issue you a tissue cover for said "officers cap" in white and khaki as well, so you can adapt your cap, to the prescribed color of tenue in a more economic way.
they don't need to issue you three of the same "offiers cap's" in different colors.

That's probably it.
I didn't change anything about this myself, as in my description it was bought like this in a pile of random cheap s***, so someone must have wanted it as a cap instead of a cover for whatever reason