Use of at least one compounds (A) comprising leuco type compound having pyrazolo[1,5-a]pyridine structure (I), azomethine type dyes having pyrazolopyridine structure (II) and their mesomeric forms, isomers, tautomers, addition salts with an acid or solvates, for the dyeing of keratin fibers, is claimed. Use of at least one compounds (A) comprising leuco type compound having pyrazolo[1,5-a]pyridine structure of formula (I), azomethine type dyes having pyrazolopyridine structure of formula (II) and their mesomeric forms, isomers, tautomers, addition salts with an acid or solvates, for the dyeing of keratin fibers, is claimed. Z 1>；S, SO or SO 2(when R 1>；is methyl), O or NR 6>；(when Z 1>；is NR 6>；, then R 1>；and R 6>；together with N form optionally saturated 5-8 membered heteroaryl (optionally substituted))； R 1>；, R 6>；H, 1-10C alkyl (optionally substituted and the substituent optionally carrying optionally saturated, 5-8 membered (hetero)aryl, which is optionally substituted) or optionally saturated 5-8 membered (hetero)aryl； R 2>；-R 5>；H, optionally substituted 1-4C alkyl, NH 2, NHR 1>；0>；, NHR 1>；1>；R 1>；2>；, OH or OR 9>；； either R 9>；-R 1>；2>；1-6C alkyl (optionally substituted)； or NR 1>；1>；R 1>；2>；optionally saturated 5-8 membered heteroaryl (optionally substituted and containing heteroatoms or groups comprising N, O, S, SO 2or CO)； at least two of R 2>；-R 5>；together with adjacent radicals : (hetero)cycle (optionally substituted and saturated)； n : 0-3； U 1>；CR or N； R : 1-4C alkyl or 1-4C alkoxy (both optionally substituted by OH), H, or (di)alkyl(1-4C)amino (in which alkyl is optionally substituted by OH)； X : OH or NR1aR2a； R1a, R2a : H, 1-6C alkyl (optionally substituted by one or more OH, 1-2C alkoxy, amino, (di)alkyl(1-4C)amino) or phenyl (optionally substituted by one or more OH, amino or 1-2C alkoxy)； either Y 1>；OH, 1-4C alkyl, 1-4C hydroxyalkyl, halo (preferably Cl, I, F or Br), O (substituted
