Say what you will about the robot designs in the Michael Bay Transformers movies, they make for one badass costume when someone puts an incredible amount of detail into it. In this case the someone is Marc De Repentigny who crafted this obscenely over-the-top costume based on the Transformers movies aesthetics.
In other words, brushed stainless steel with lots of pointy metal corners. But it seems to work here, and that's probably due to the awesome details Marc included like moving eyes, glowing thrusters complete with exhaust steam, and a voice controlled animated mouth piece. In six months he's sure to win any Halloween costume contest he enters.