| abstract |
Disclosed are substances which contain unsaturated, non-aromatic dialdehydes of formula (Ia) and/or the tautomer (Ib) thereof, wherein R<SUP>1</SUP>, R<SUP>2</SUP>, and R<SUP>3</SUP> are defined as indicated in claim 1, along with at least one CH-acidic compound of formulas (II) and/or (III), wherein R<SUP>6</SUP>, R<SUP>7</SUP>, R<SUP>8</SUP>, R<SUP>9</SUP>, R<SUP>10</SUP>, Y, X<SUP>-</SUP>, Het, and X<SUP>1</SUP> are defined as indicated in claim 1, in a cosmetic carrier. Said substances color keratinous fibers, especially human hair, in an intensive, colorfast, natural brown shade. |