Not sure this line is correct:
"The teeth and vocoder are painted the same dark, gun metal grey as the mohawk"
In this picture the teeth and vocoder definitely look to be a black color. Teeth look the same color/finish as the rest of the helmet and the vocoder looks to be a satin/matte black. Hard to see the mohawk, but every other photo shows it to clearly be a dark grey/gunmetal color.
You can see in this picture that the mohawk is a lighter color. It looks like the mohawk is a grey/gun metal color, and the teeth and vocoder are a satin/matte black finish, similar to how the vocoder is on regular Stormtroopers. If anything, I could see the teeth being the same color as the mohawk, but would definitely have to be a dark gun metal. No pictures show the teeth being a light color like how the mohawk is seen.