[S. Sebok]

Allright I managed to get a GDFB maille coif for Christmas. I am pretty satisfied with it due to it not having a gaping neck hole and it fits my head rather well, except one thing, it's metallic grey. I would like to know how to blacken it to match my already blackened hauberk and overall my whole kit. In case you're wondering I would like the degree of blackening to match the Icefalcon maille, which I'm unsure how they do it but it may be through a chemical. Any suggestions on how to blacken it?