I started hennaing in 2004, with BAQ henna purchased here. After 3 years of deep red/burgundy, I tired of it and decided to incorporate indigo to mimic my previously (salon-dyed) coffee bean brown (at the time I decided to do this, I was about 50% gray and so the "red" was getting brighter than I wished).
I used many different indigo processes and combinations. I've used two-step, mixed amla in, tried hendigo (fades quickly on gray hair). Cut most of it off, let the growout be root-touch-ups with hendigo only vs. doing whole head, 2-step henna-indigo apps (thus getting rid of opaque black), but still darker than I wanted. I had black hair, and it didn't suit me.
Last 2 weekends, I experimented with removal/fading. Here are my results
Methods and Results
Weekend 1: 2 shampoos with baking soda: Wetted hair, applied cheap shampoo (Suave), added handfuls of baking soda, lathered. wrapped in plastic bag then towel (for warmth), left in 10 minutes, rinsed well. Thought I saw slight brownish tint in water. Repeated. More brown water in second rinse. Conditioned briefly and dried. Result: I noticed a *slight* modification of color. Roots (most recently hendigo'd) definitely faded. Hair dryer than before, but not too bad after conditioning. Very tangled.
Weekend 2: 3 shampoos with baking soda. Most brown on second shampoo (quite a bit). Immediately after, saturated hair in cheap conditioner (Suave coconut), rubbing in well and pulling through ends, squeezing it and drawing hands down to ends. Drip-off of conditioner was bringing out even more dye. Wrapped and left to sit for 1 hour. After rinsing out and wrapping in a towel, I noticed a lot of orange streaks on the towel: henna! From my roots! (now faded to natural gray). Result: I noticed definite modification, edge taken off black, more natural looking. A "warm black" or deepest-darkest brown. But still too dark. Still, I saw progress. Hair very dry.
Tonight: 2 Vitamin C shampoos: Wet hair. Added cheap shampoo. Lathered in 2 handfuls of Vitamin C powder (you can buy it this way). Wrapped in plastic bag and towel. Left in 1 hour. Rinsed. Repeated. Water clear after both shampoos. Hair very clean but not feeling tangled, just a little dry, as after a normal shampoo (with cheap shampoo). Saturated with cheap conditioner, wrapped, left in for 1/2 hour. Rinsed and dried. Figured since no color in rinsewater, that at least I got my hair clean and reconditioned; felt better than before baking soda treatments. Result: Amazing... the color has actually faded to an espresso color! For the first time since before I henna'd, I have brown hair.
Still darker than what I would like, but now I know I can fade it more.
And... I have to redo these gray roots (I need to figure out that mix; probably hendigo/buxus in one step will match what I have, timed properly.
So, there is hope. If my layers and years of indigo can fade, yours may be able to, too. I'd recommend trying the Vit C first -- easier on the hair.