I haven't built one up in a while, but I used Krylon Satin Black, and then ever-so-carefully dusted it from a distance with some Krylon Chrome to get the metal flake look. If Kylash327 sees this thread, maybe he can remember what he used - it was a really nice metallic black that I was never able to get my hands on.
I went with Duplicolor Graphite Grey metallic.
The official replicas are not black, but dark grey most likely exactly the same as the TV props.
They are also misted with a little silver. I was going to do this to mine, but decided to do the solid color (with flat black inside the barrel).