The main reason that reds fade so quickly is that many years ago the FDA determined that the red dye stock molecule we used in our industry caused cancer in laboratory rats when you gave it to them in ridiculously excessive amounts. My thoughts on the subject were that rats already have a rough life, why would they want to make them live in a cage and deliberatly cause them to get cancer?
Back to the subject, the dye stock that they replaced had a smaller molecular size than the one that they replaced it with, wich allowed it to penetrate deeply into the cuticle layer of the hair shaft giving it a better chance of staying in the hair for a longer period of time. The one that we are currently allowed to use, with it's larger molecular size, sits in the outer layer of the cuticle where it washes out of the hair more quickly.
Another thing to consider is that the very bold, intense colors that are popular with some of our younger guests are only designed to stay in the hair for eight to ten shampooings. So,if you are looking for a more permanent color they are not a good option for you to choose.
Sun and heat are an artificial redheads worst enemy.Keeping your hair covered during the sun and fun of summer is not always practical but it will slow down the rate at wich your color fades. Check your water temperature when showering or bathing. To some, a scalding hot shower feels good in the morning but it will make your color fade faster.Keeping your hair in optimum condition by using a professional shampoo and conditioner will help you keep your color longer. Check with your stylist as to what products will work best for your hair.