Question: how to lighten dark dyed hair?
Answer: Use a Clarifying or Lightening Shampoo to Bleed the Color Out. For very mild cases, washing with a clarifying shampoo a few times will usually fade it to a nice color. ... 
Use Baking Soda. ... 
Use a Color/Dye Remover. ... 
Use Bleach Shampoo. ... 
Other Solutions.