Rule of thumb is that you can't /shouldn't colour over henna, because it's a a metallic salt and when you apply peroxide it can cause an exothermic chemical reaction. Do an incompatibility test and this will show what reaction will happen when colouring the hair. I had a client a few months ago and the only thing I could do was match her roots with a semi until we cut the henna out and now we've started lightening it. I've been longing for a product that helps to remove henna but I'm unaware of any.
That's what I meant incompatibility test I'll get that done see what the outcome is ive never encountered henna yet not something I see alot of where I work thank you
I've only got two from the back section from either side. I'll see how they come out thank you
If the clients applied the henna themselves the front sections are likely to be more saturated.
She told me she had it done at a hairdressers in Pakistan
I've done a incompatablity test and it slightly foamed heated up them went cooler no fizzing or anything else so we were still undecided so we applied bleach and 30 vol ( what I would have done for her foils) and it expanded and that confirmed it no colouring service to go ahead thanks for the advice
Heat alone, or foaming is showing signs of a chemical reaction, so for future reference that's enough confirmation
