This was labeled "#4" - so I don't know what the name is.
What I can tell you is that reducing it hot or cold makes a big difference!
This is a clear core, encased in #4. At this point - I didn't know if I was dealing with a striker, or a reducer. So I heated it to clear hot (mostly, anyway), and then struck it. Didn't do anything. So then I tried reducing it. It quickly developed a metallic surface. I reduced it again. Et voila!
Still checking for striking, I made the two on the left, heated to clear, then made bead, and the two on the right, I made much cooler. I struck all four, and then reduced the two on the right. Which you would never guess from the colours.
In cross section, the rod has multiple layers (rings) - so I'm not sure how that effects the colours you get either. The colours I got are interesting, but I think further practice with this one is in order to see if I can get anything brighter, less moody-broody.