How do I wash permanent hair dye

If you had your hair coloured at a salon, you can use any shampoo, although I suggest buying shampoo such as Wella colorsaving shampoo or Bumble and Bumble color shampoo.
If you have coloured your hair using an at-home kit, use the shampoo/conditioner provided in the kit, then purchase something from Wella or Bumble and Bumble. I recommend buying Bumble and Bumble, as that is what I use, and I've found it to be the best yet.

-m

Permanent color fades with each shampoo. If you want to perverse your hair color, wash your hair with shampoos and conditioners designed for color-treated hair.