Rustoleum Weathered Wood. It is "Roof Accessory Paint". I can't take credit for finding it though, member Scotch suggested it on another thread. I couldn't find it at first so I tried some other colors that actually looked better according to their caps, but they weren't great. Eventually got the weathered wood and it looks best for sure. The cap looks a little more brown, but it ends up a nice grey. I did all four door speakers. I might do the subwoofer too eventually.what color is that paint? It looks great!

Rust-Oleum Stops Rust 12 oz. Weathered Wood Roof Accessory Spray Paint 285217 - The Home Depot
Add extra protection to any surface in your living space without any effort by applying this unique Rust-Oleum Stops Rust Weathered Wood Roof Accessory Spray Paint.
www.homedepot.com