We all know what the color black looks like, but technically it's defined by the absence of light. Total darkness.
Black is most commonly used as an adjective, but you can also use it as a noun, like when you say, "The actors wore black." Synonyms when used to describe color include inky, raven, and sable. This word can also refer to an angry feeling, as in a black mood, or something wicked, like black magic.