HENNA - black to brown?

I have natural black Asian hair, and I want to change it to some thing like a dark brown to just brown (not too light) but I'm only able to use natural dyes. I've been reading many Henna articles saying henna will just make it red. But is there another type of powder I can mix with the Henna to make it this brown color? Such as Indigo. I don't mind if it will take a long time.