The agent for coloring keratin fibers, especially human hair, contains at
least one common cosmetic additive; an oxidant, such as hydrogen
peroxide; and at least one naphthalene derivative of formula (I):
##STR00001## wherein A.sub.1 and A.sub.2 are different from each other
and, independently of each other, each denote a partial structure of
formula (II), (IIIa), (IIIb), (IV), (V), or (VI): ##STR00002## E is O or
S; Y is N or a quaternary nitrogen atom substituted with a
C.sub.1-C.sub.6-alkyl group, a C.sub.2-C.sub.4-hydroxyalkyl group, or a
C.sub.4-C.sub.6-polyhydroxyalkyl group. New naphthalene derivatives are
also described.