Need help with character - Cyber

[dividebyzero]

As my first character, i thought i would start off easy and do Cyber.
Im kinda stuck on doing the metallic arms right now.  Im using Hugo as a base for his upper body and SNK-Hugo for the arms (since they have more shading- better for the metallic look) however im less than satisfied with the look.  I have basically a grayscale of his arms but it doesnt look quite metallic- just grey.  Can someone help me out with a palette for SNK Hugo that would have a more metallic look?