I was at the salon today and ask for subtle purple highlights... instead my entire head dyed a bright purple. I want to remove it ASAP before I go to work tomorrow. Can I wash my hair and then use a box color of medium brown to get rid of the purple? What will happen when the color fades? Will it severely damage my hair?

Unfortunately, dyeing your hair so soon after an initial dye will damage it, no matter what dye you use. If you use a semi-permanent box dye over the purple, the damage to your hair will be minimal and repairable, but the brown may last only 6-8 weeks. The good news about this though, is that by the time the brown begins to fade, your hair will have 'healed' to take a full permanent shot of brown again!

My advice would be to use a semi-permanent box dye, and find a hair mask or repairing conditioner (I would recommend MoroccanOil or L'Oreal) to use until the damage subsides.