Dyeing keratin fibers, preferably human hair, comprises (a) applying a reducing composition containing reducing agents and an oxidizing composition to the fibers, (b) optionally rinsing the fibers, (c) optionally washing the fibers with shampoo and then rinsing, (d) optionally drying the fibers to dry, (e) applying a dye composition comprising one or more natural dyes in a medium on the fibers, (f) optionally washing and rinsing the fibers, and (g) drying the fibers.