Have you ever wondered why so many architects wear black? Well, Cordula Rau definitely did, so she went ahead and asked a bunch of architects that questions. And she made a book out of the (sometimes hilarious) responses she got, which is adequately dubbed "Why do architects wear black?".
My answer is that black clothes form a nice contrast with the modernist white building. Who is responsible for the white modernist building? I'd have to call on Le Corbusier as trendsetting. And he probably was also on the forefront of trend to start wearing black. I'm glad that he was less successful in starting the trend of "painting the houses of fellow architects, while being nude" - but that's a whole different story alltogether.
I found the book by Cordula Rau through http://architecture.myninjaplease.com The first image is found through them, too - and they have it from architecture students from hell.