Firstly I know IABU for posting this here but I need help quickly 
My hair is a murky blonde/brown colour. It has been bleached to blonde in the past (about 5 years ago) don't know if that's relevant. Today I've put a light blonde dye on it and I don't like it
It's got an orangey tint to it despite washing it with purple shampoo, and it's just too light, it doesn't look right against my skin tone.
So I call upon the wisdom of mumsnet, can I go to Boots and buy a brown dye to cover it? Or will my hair fall out/go green or something bad?