Apply coffee, tea, henna or the hulls of black walnuts to naturally dye hair a darker color. To dye red hair a darker shade of red, apply hibiscus, rose hips or the juice of carrots or beets.
To dye hair a dark brown or almost black, make a strong brew of either black coffee or black tea. When cool, pour it over completely clean hair, cover with a shower cap and let the mixture remain in the hair for about 20-30 minutes before gently rinsing it out. Repeat two times per week until the desired color is achieved and once per week after that to keep the color vibrant.
Henna can dye hair to a dark brown or reddish brown shade, while also nourishing and conditioning it. Buy natural henna powder and make it into a thick paste the consistency of very wet mud. Leave it in the hair for about 5 hours or even overnight before rinsing with a mild shampoo for colored hair. Repeat the henna treatment twice per week.
To use the hulls of black walnuts to darken hair, crush the hulls and soak in boiling water for three days before applying the mixture to hair.
To darken red hair or get dark red highlights, boil either one cup of rose hips or 3 bags of hibiscus tea in two cups of water. Strain the mixture and massage it into the hair. Repeat as required or 2-3 times per week. Natural redheads can use beet and carrot juice, either separately or together, to add depth to their existing color.