I have very short 4c hair which is black. I have heard of the benefits of henna, im primarily interested in the strengthening effects of it, but I don't want to dye my hair red, I want to keep it black. I've done a little research and it seems that i have to add indigo to it so that my hair stays black, but it seems that it still might change the colour of my hair which I don't want. The other option it seems that I have is using cassia but it seems that it isn't as strengthening as henna. Could someone point me in the right direction