And it works better each time and lasts longer. I now leave the henna on for 3 hours and the indigo for 1 hour and 15 mins. It's a very dark ash brown. I can see how you could get black, even a blue black if you just leave it on longer. It lasts about 6 weeks before it starts to fade significantly, and by then my roots need attention, anyway.
Love this! I just wish it didn't take so long