"And for some reason, I got blue hair. You gotta have blue hair."There are plenty of ways to differentiate characters from each other, but one of normally limited utility is hair color. Human hair has a limited amount of variation, after all, not enough to make everyone on a half hour show once a week easily distinguished. Thus, this trope was born, so that artists could use the full spectrum of color. It's so common that it's mostly considered an Acceptable Break from Reality now. This is especially common in anime, where characters often have impossible hair colors. This started with manga series that used distinctive colors on the covers to make characters stand out, even though they all had either dark or light hair in the actual black-and-white pictures; anime brought it to the screen and made it a standard part of character designs. There are several reasons why artists do this. The first, noted above, is to help distinguish characters from each other, as with Anime Hair. It may be done to indicate character personality, such as an Emotionless Girl with blue or white hair. It may indicate that a character is unique, if they are the only one in the cast with their hair color. Or it may be done just to suit the artist's taste for variety. Some specific colors have subtropes which ascribe certain character traits to them: a blue-haired girl may be shy; a Rose-Haired Girl may be cheerful or passionate or sweetnote ; a white-haired young man is often evil. Subtrope of Hair Colors. When hair is depicted as an odd color, but is supposed to be a normal color (e.g., powder blue standing in for grey), that's Hair Color Dissonance. When the hair color is realistic but is not justified by the setting, that's Implausible Hair Color. See also Mukokuseki and Amazing Technicolor Population. For characters with impossible hair styles, see Anime Hair. When the hair grows very fast, it's Rapid Hair Growth.