I actually love dark n lovely natural black and jet black for coloring virgin hair but the key is conditioning the hair. Anytime you color hair whether you are going light or dark the hair will be dry due to the coloring process. When I color hair I shampoo it 3-4 times with Suave humective shampoo for dry hair (professional line) and after all the color is gone then I use Suave humective conditioner for dry hair and I leave a lot of conditioner on the hair and let it sit about 10 minutes. After I do that I rinse the hair in cold water because cold water closes the cuticle of the hair. Ive done this to my friends hair because she only wears jet black and our hair comes in a natural color which is lighter. I do this for my sisters deep wave too and their hair is very soft but I do tell them to condition it at least once a week though.
If your hair is colored and curly I would suggest conditioning it about 3 times a week because curly hair is drying anyway. If it is straight/wavy then once a week would be great. If you try Suave professional line conditioner you will notice that the hair wont be as dry and it will have a nice feel and luster to it.