If you're at all familiar with Sherlock Holmes then you've no doubt seen the odd capes, high hats, and Tweed suits of the often misunderstood, highly functioning sociopath who has an uncanny ability to solve any crime no matter how "unsolvable". This version of Sherlock Holmes isn't wearing stiff white collars and top hats. Instead the new Sherlock is young--albeit still sickly pale--and his wardrobe has evolved with him. He wears a utilitarian uniform of sorts. He is rarely seen in anything other than a black double breasted overcoat and wool fringed scarf. His black suits and lapels have slimmed down to be razor thin. This is combined with a white shirt and a shrunken collar worn open with no tie--or ascot for that matter. As much as the new Sherlock is on the run this uniform suits not only his personality but his profession. Dark, solid, unadorned, and functional. He doesn't have time to fold pocket squares, tie knots, and polish shoes while he's chasing down serial killers and investigating psychopaths.
His sidekick Watson lives much of his existence in a similar uniform. A black waterproof, synthetic, or waxed jacket with a suede collar and shoulder gun flap. It looks to be something from Hackett. In most episodes the jacket covers a gray cable knot crewneck sweater layered over an unassuming button-down collar shirt. Watson is often two steps behind Sherlock on the crime scene, but he is on par with his uniform.