I am new to this site. I have colored my hair twice in the past 3-4 months with henna. I wanted to go to a more natural hair color product. I have naturally curly hair. But since the henna my hair has seemed to have lost some of it's curl. And it is very dry. I have quite a bit of gray at the front and temple areas. So, I was going to try a semi-permanent hair color NOT henna. I was only going to apply the semi-perm to the gray areas not my whole head. Does anyone know how long after using henna it is ok to try a chemical semi perm? The grays are all gray again, not red from the henna. I just don't want to turn my hair some crazy color ... Also, will the curl returned?