Color treated, or dyed, hair requires special care and maintenance. People with colored hair usually have to do a lot more than people who haven't done anything to their hair. The reason why colored hair has more problems is because when the hair is colored, it creates holes in the hair, these holes are prone to being damaged more so. There are 3 main things that dyed hair needs: Help from physical problems, moisturizing abilities, and a way to ensure that the color lasts a long time.
One way to prevent breaking your hair is to pat it dry or let it air dry on it's own rather than bundling it up in a towel. If you must brush your hair when it is wet then you should use a wide toothed brush or comb. Some people want to blow dry their hair but this is not the best way to dry it because it can dry out your hair fast or create static electricity.
Using conditioner after each time that you wash your hair will help it remain healthy. Using hairspray can provide an extra layer of protection for your hair if it contains vitamins or conditioner in it (most brands have them added now). If you want straight hair then you should get a deep conditioning package from a salon every week. While at the salon you can get a glaze treatment that will not only make your hair stronger, but it will help keep your color longer.
If you wash it too much then it will speed the the rate in which your hair color fades. There are special types of shampoo and conditioner made for dyed hair. Some conditioners are able to color your hair or add a hint of color to retain its current color. Some conditioners are necessary for protecting your hair from the sun since sun light can damage hair extremely quickly.