Does being dehydrated make your hair look dry?

Does drinking more water bring more moisture to your hair or does the moisture in hair come more from conditioner, dietary fats...??? Help plz cause I have colored my hair and had an erratic diet for awhile. I need to know how to rejuvenate my dry, colored hair as soon as possible. I don't eat any fat, much meat, and I heard also that those two things play an important part in making healthy glossy hair.