Home remedies for darkening the hair include curry leaf or hibiscus oil treatments and amla oil. Hot oil treatments take away the red tinge the hair develops when in need of nourishment.
To use the curry leaf treatment, place curry leaves in hot oil and allow the mixture to sit for a week. Rub the oil into the hair to restore its dark color. Create hibiscus oil by allowing hibiscus flowers to sit in hot oil for a week. Another possibility is to comb amla oil through the tresses to darken the hair or apply the juice of the amla fruit after oiling the hair.