How do you get permanent hair color off your skin
Try 3% hydrogen peroxide, the kind used as an antiseptic. There are also hair dye stain removers available from beauty supply shops, Fanci-Full Haircolor Stain Remover is just a couple bucks.
I have no idea, but it sounds like any method is going to be painful on you.
I'm NOT suggesting that you smoke, but if you can gather cigarette ashes, gently rub it on your skin where the dye is and it will take it off. My hairstylist told me about it.