My hair was a blonde with a hint of red and I mistakenly dyed it a light ash brown. Now my hair is grayish, dark brown almost black in some parts. I can't afford to have my hair stripped and I need to fix this. It is horrendous. I wanted to go back to my natural brown hair color. I have heard that Head and Shoulders works but I was wondering if I should just dye it a medium brown to cover it up.