Is pure henna really permanent?

So i ahve hennaed my hair 3 times before but i would shampoo when washing it out, so it wouldn't be permanent and would totally wash after two showers, now i thought i'd be awesome with red shades so didn't shampoo and let the dye oxidize, i wish i didn't , i ahve almost balck hair and when hennaed it's the same but under light, it has a reddish gloss which i hate , and i wanna remove it , and actually every time i shower , when washing my hair the shampoo washes out and the water is orange, so does that mean that with repetition it'll come off? (btw it's pure pure henna because I'm Egyptian and pharaohs were the first people to use henna for such stuff so we get it pure and don't get tricked by compound henna)