I was going to link you to the same place. I tried a few different powders in my sidearm run. It is interesting stuff. You can also affect the color by how much powder you use and what your start material color is.
The reason I asked was I'd love to do an Open Seasons-style Mando (maybe a real Deathwatch) one day. I've seen Jasters done in metallic but personally I think it's too close to Jango in metal color.