A hair salon offers semi-permanent hair color, or you may do it yourself at home. However, as with all hair color, sometimes the result isn't desirable. The typical four to six weeks that it takes for semi-permanent hair color to wash out may seem too long. A few methods may speed up the removal of semi-permanent hair color at home. If you act within the first 72 hours after coloring hair, you should see the best results.
Lather up hair with an anti-dandruff shampoo, such as Head and Shoulders or Selsun Blue. Let the shampoo sit on the hair for 30 minutes before rinsing with warm water. Repeat.
Wash hair with a clarifying shampoo, which is meant to remove impurities and built-up residue, as an alternative to dandruff shampoo. Leave on hair for 30 minutes, rinse and repeat.
Add 1 tsp. dishwashing liquid to 2 tbsp. shampoo, and massage into the hair and scalp if clarifying or dandruff shampoo does not remove hair color. Leave dishwashing solution on the hair for 30 minutes, then rinse with warm water. Repeat.
Follow the clarifying treatment of your choice with an intensive hair conditioner, and leave in hair for up to 30 minutes to help restore moisture to the hair shaft.
Use a blow dryer on a high setting and spend time in the sun, as heat will help fade the hair color.