Advice on Highlighting Metallic Contrasts?

[Draco Mundo]

Basically, I used a red contrast on top of an undercoat of Runefang Sliver, for a really cool metallic look. The problem is, I can't decide how to Highlight this thing! Do I do a lighter metallic, followed by a red layer? Or something else entirely? Pics of the W.I.P. attached. Pre-emptive thank you to you all!