How regain black hair and how get strong and long hairs?

Use Black dye: Since there's no such color in the human genome for BLACK HAIR you'd need either a spray paint can or buy a wig if black is the color you want. Long hair? You need to wait, however, long it takes to grow your hair out. If you want strong hair then, you need to make your hair exercise with you in the gym or simply eat a well balanced diet & not mistreat your head with chemicals and blowdryers.

For hair health but: not change of color > Get adequate sleep,avoid excess sugar & fat, v carbonated drinks, eat enough protein, exercise regularly. Insure you have adequate Iron (like kale & other dark green leafies), Omega 3 fatty acids (like walnuts),vit.E (fruits & veggies), D & B vitamins, biotin & zinc. Avoid sulfates & formaldehyde in shampoos, excessive blow dry heat & curling irons.