Giants helmet paint

[DANDY DON]

I'm painting the current Giants dark unis and want to know what other painters are using for the Gmen's helmets.I use Folk Art ultramarine blue for the jersey's (which I really like) but the helmets seem to be a slightly darker/metallic blend...One thing I have tried is adding a pearlizing agent to the Ultramarine blue which isn't bad but I think I can get closer...Any ideas?