The black craze really stared with the 901. With it's shiny black exterior and blue light, it was easy to tell it was not a cigarette. When the 510 came out it was called the Yeti, probably because the all white model made you think of the abominable snowman (see picture below). While I still call it the Yeti, you won't find a lot of white ones showing up.
So many people want it to look exactly like a cigarette when they start, but then they want the exact opposite. As for the 510, I prefer to change just the atomizer or carts. Put a white atomizer on a black model and you get a Daffe 510. Put a round white cart on a black model and it looks just like a magic wand.
Take if from this little black duck. Black is the new black.
--Prof Daffy