The belt and pouches are British military, and the buckle was made by Planet Replicas. They actually provided the belt and pouches too.
As for what paint was used, I'm not sure which part of the costume you are referring to, but a variety of paints were used. Most of it was done in the UK by Planet Replicas and I'm not sure exactly which paints they used.
For the items I did, like the boots, I didn't use spray paints at all. It was special acrylic for leather made by Angelus brand. It was put on with a brush (use a camel hair brush - like the kind used for makeup) in order to hide the brush strokes.
The color was custom blended by mixing green, black, and maybe one or two other colors (can't remember at the moment).