I'm using the Fountek 89's for my pods and the finish is black. Not sure how he does it, looks to be black aluminum. He also does leather pods. My pods are drilled out for different kind of drivers...threaded holes.
I might ordered a pair of 3.5" to 4" pods and have him designed it in a way, where i'll be able to mount any driver I want under 4" diameter, using like a 1/8" or 1/4" speaker ring. That way, I'll have the flexibility of swapping out drivers if I ever change them up.