All while Antonio Brown should have been at Raiders camp with his now former teammates, he was busy battling with the NFL over his helmet. After two grievances were heard by the league, and both were shot down, he miraculously decided on a helmet and returned to practice.
The helmet he decided upon was called the Xenith Shadow and he and the company made quite a big deal of his helmet selection. he had a photo session with the silver helmet and everything. Even made it his twitter avatar.
And as it happens, the very next day, Brown began his most aggressive efforts to date to force his way out of Oakland and onto another team which also (probably not coincidentally) wore a silver helmet.