Question: how often can you dye your hair with nice and easy?
Answer: Can you colour your hair too often? Demi-Permanent haircolour will last up to 28 shampoos—if you wash your hair every day, that's about 4 weeks. Permanent (lasts until your hair grows out or you recolour) haircolour should be refreshed when your roots start to show, about 4-6 weeks.