Hi guys my auntie has been using a black box colour for a few years and when I saw her after 6 months was shocked to see she has 6 inchs 100% grey and rest jet black, she says she had a bad allergic reaction pus coming out of ears. Swollen face, and didn't want to touch it again. I want to do her hair it looks quite bad, yes I'm trained, now I want to cleanse the black out. And use something like wella 6/75 6/73 all over. Now what my question is. What should I be looking for when I've done the skin test as ones I've done before on others come up slightly red. Infact all the ones I've done when I was in college come up red but we took this as fine to carry out service. What would a genuine reaction where you would not carry out a service come up like on the skin please? Thx