response: Many hair colorings are done professionally.
history: Seems like hair coloring is really popular among college girls from what I've seen. Oh, is that so? I know that the practice of changing hair color can be called hair coloring or hair dyeing. Yeah definitely, it may be controversial but it seems like bisexual/transgender/gay women do it all the time, at least from what I've seen.
knowledge: Hair coloring can be done professionally by a hairdresser or independently at home.