The invention relates to a method for dyeing keratin fibers, especially
human hair. The inventive method comprises the following steps:
optionally applying a pretreatment agent M1 to the fiber, using a dye M2
on the fiber which is optionally mixed immediately before application to
the fiber from a component M2a, containing at least one oxidative dye
pre-product of the developer type and/or an indole and/or indole
derivative and a component M2b, containing an oxidative dye and/or an
enzyme. If desired, a third agent M3 is added to the individual agents
M2a or M2b before mixing them or to the mixture M2, and said dye M2 is
rinsed from the fiber after a period of 5 10 minutes. At least one of the
agents M1, M2a, M2b or M3 contains a compound from the vitamin B6 group.
The invention further relates to hair pretreatment agents, to agents for
dyeing keratin fibers, to their packing in corresponding kits and to the
use thereof. The inventive compounds of the vitamin B6 group and their
physiologically acceptable salts are useful as coupling components in the
production of oxidative dyes that contain conventional developer and/or
coupling compounds and/or indole and/or indole derivatives in a substrate
appropriate for dyeing. The inventive compounds are further useful as
active substances that improve the hair structure.