What is the way to make hair darker without using dye?

Coffee can be used to darken hair without dye. Users should soak their hair in leftover coffee for several minutes.

If the hair is not as dark as desired after soaking it for several minutes, users can soak it for an additional few minutes. Used coffee grounds can also be used to darken hair. To use coffee grounds, users can scrub the hair thoroughly with the grounds and let them sit for several minutes before rinsing them out. This can be done on separate strands to give the hair highlights as well. Coffee does more than just darken hair as it gives the hair a shiny appearance, too.