Henna Tattoo

Shalom to the devoted and holy staff of Hidabroot, I would like to ask you a question regarding henna tattoos. Is it halachically different from a permanent body tattoo? Is it permitted? I am referring to a henna tattoo that disappears after some time, or after a few years or a few months. Is that also forbidden? What is the general prohibition regarding tattoos, the prohibition of cutting or engraving into the body, since henna is a coloring... Is the deciding factor in the prohibition the manner in which the tattoo is created, or the length of time it remains on the body? 

Thank you very much, Moriah.