A laundry detergent composition comprising: (i) from 2 to 70 wt. % of a surfactant; and (ii) from 0.00001 to 0.1 wt. % of shading dye which is covalently bound to at least one alkoxy-CH.sub.2CHO or —CH.sub.2CHO capped polyalkoxy group.

A laundry detergent composition comprising: from 2 to 70 wt. % of a surfactant; and from 0.00001 to 0.1 wt. % of shading dye which is covalently bound to at least one alkoxy-CH═CH.sub.2 or —CH═CH.sub.2 capped polyalkoxy group.

The present invention relates to azo dyes of formula ##STR00001##
wherein R.sub.1 denotes C.sub.1-C.sub.12 alkyl which is unsubstituted or substituted by one or more C.sub.1-C.sub.12 alkoxy groups, hydroxyl groups, amino groups, cyano groups or halogen atoms and which may be interrupted one or more times by the radical O, S, NR.sub.4, COO or OOC; R.sub.4 is hydrogen or C.sub.1-C.sub.12 alkyl; either R.sub.2 is cyano and R.sub.3 is halogen or R.sub.2 is halogen and R.sub.3 is cyano; and Ar represents a carbocyclic or heterocyclic aromatic radical, to the process for the preparation thereof, to mixtures containing said dyes and to the use thereof in dyeing or printing semi-synthetic and especially synthetic hydrophobic fiber materials, more especially textile materials.