And hey, waddaya know, I actually follow through.
The purple there is a single layer of the createx iridescent purple applied by brush over a black basecoat. A bit sloppily, too, but I was getting kind of bored by that point. Please do not judge by the rest, as it's unfinished. I figured this would show off the really interesting bit-the iridescent purple-better than doing all the trim and whatnot over it.
So yeah, basically metallic, but with a few hints of crazy color in there.