Hair that is colored is more porous and finds it hard tonsils in to moisture. The strands are also weaker than when they are in their virgin state.
Maintenance must consist of regular treatments with conditioner mixed with oils such as 100% pure olive oil, black castor oil, avocado oil and many other natural oils that have moisturizing and strengthening properties.
Unless you are going to blow dry and flat iron the hair, I recommend skipping regular shampoos and stick to co-washing and using cleaning conditioners such as Wen by Chaz Dean