Painting Bricks around insert.

[Tom Pencil]

Before the new mantle goes up I want to paint the Fire bricks that are exposed around my Harman insert. If the brick were old looking I would keep it but since they are the semi-glossy fire brick I think painting them is a better option for looks in my situation. I bought Rust-oleum High Heat Paint but the brick do not get hot and the can says to not use primer. Or should I use a primer paint and buy flat black as a top coat? Should I do anything special to prepare the bricks other than cleaning and drying before painting?

Thanks
Tom