Black is a perennial favorite with all kinds of people. First off, there is the unstated rule in New York City that if you want to look like an adult person, you have got to wear black. Secondly, there is the rule that if you want to look tough at all, you have also got to wear black. Black is just the kind of color which says that you have power, not only over yourself but also in the world around you. If you wore any other color, you would almost look incomplete in a sense. But with black, a person just looks better put together.
Simply put, black is pretty much the only color which is always going to be in style. There is no other color which can adequately express that a person is tough, powerful, or mature. Would you respect Darth Vader if he had worn red, even if it were a tasteful red such as a bergundy? If he had worn blue or white, his character would have looked completely incongruent. However, in black he looked just right. This is because powerful characters have no other reasonable option than to wear black as much as possible.
The ironic part of it all is that black, while it goes well in just about every situation, is not universally worn. There are some people who actually like to integrate other colors into their personal fashion palettes for some strange reason. And while there are no formal rules about how you need to wear black, it is up for debate whether there are any other colors which can even compete with black, both for style and for how much it says about a person’s character. You just do not get the same kind of pathos if you wear yellow or something. Black will never go away, because it is just the most expressive color.