what is the difference between demi permanent and semi permanent?
Demi Permanent Vs. Semi Permanent Hair Color. Both demi-permanent and semi-permanent hair color dyes can be applied at a salon or at home. The main differences between demi and semi-permanent hair color are the duration the color lasts and how the dye penetrates the hair shaft. Semi-permanent hair color does not contain any peroxide while demi-permanent hair color may contain low levels of ammonia or peroxide.