Bleach and dark streaks

This would be a geed thread to get suggestions https://www.hairdyeforum.com/index.php/topic,11009.0.html

Though it’s aim is to stop colour fading, it’s actually the same way to stop colour bleeding.

It does it immediately when I rinse the color out, I've tried doing the dark and a few days later redoing the blonde but that is just a lot of work, I rinse with ice cold water in the sink and it still bleeds. I'm curious if it is the particular dye that I'm using.

Unfortunately bleached hair is very porous and so can suck up the dye as it’s being washed out. You could try putting coconut oil on the bleached parts when dying and rinsing out the black. It will hopefully cause a barrier. To get it out, use lots of conditioner. T sounds odd, but it works as well as, if not better than, shampoo.