the GPR lock comes in a darkish brown colour. the barrel was left in-the-white, as i always do, to patina on its own. though i've completed a lot of barrels and locks in both plumb brown and blue-brown, i'd rather leave all the metal to patina on its own, naturally, over time. "back in the day", it is argued that most of the time the metal was left untouched and as-is, and thus as such is quite "period/era correct authentic", for those who feel the need to be historically "correct".