>>3367595>>3367603>>3369968I don't know why I'm surprised that /p/ doesn't have even rudimentary knowledge of camera history - just like every time I see blind hatred of Sony, whose cameras are effectively made by Minolta, who in turn are an older and more storied company than even Nikon.
Anyway: Cameras were originally constructed from brass. Brass turns a nasty greenish colour if you don't polish it practically on a daily basis, so camera makers in the early days would paint the brass parts with a hardwearing black finish to save the consumer the trouble - also with a lot of early photography being confined to the studio black was the logical choice to cut down on unwanted reflections. Eventually chromed brass was introduced and became a standard. Black camera bodies and lenses started getting popular with professionals again in the 60's ("It Aint' Me" starts playing), with many companies charging a standard $35 fee for "professional" black finishing instead of the standard chromed brass option. Through the 70's and 80's, black became the colour associated with photographic professionalism, then when the switchover to plastic bodies began camera manufacturers quickly realised chromed plastic looks like reheated ass and stuck with the "pro black" look.
Tl;dr black has always been the colour of "professional" film equipment for a variety of practical and circumstantial reasons.