A highly crosslinked polysiloxane dye comprising at least 10 Si atoms, including at least one moiety of the formula (I) whose open Si-bonds each are linked to an oxygen atom and open O-bond is linked to a silicon atom in the rest of the polysiloxane, and wherein T is a direct bond or an organic spacer group such as C 1 -C 18 alkylene, C 2 -C 12 alkenylene, C 5 -C 10 cycloalkylene, C 5 -C 10 arylene, -C 5 -C 10 arylene-(C 1 -C 10 alkylene)-, each of which may be end-capped towards the linkage to Dye by CO, COO, NR 1 , CONR 1 , NR 1 CONR 1 , CS, CSS, CSNR 1 , NR 1 CSNR 1 , O, S, SO, SO 2 , C 5 -C 10 cycloalkylene, C 5 -C 10 arylene; or T is C 3 -C 18 alkylene interrupted, and optionally end- capped towards the linkage to Dye, by CO, COO, NR 1 , CONR 1 , NR 1 CONR 1 , CS, CSS, CSNR 1 , NR 1 CSNR 1 , O, S, SO, -SO 2 -, C 5 -C 10 cycloalkylene, C 5 -C 10 arylene; or is CO; (CH 2 CH 2 -O) 1-5 ; COO; N(R 1 ); CON(R 1 ); O; S; SO; SO 2 ; R 1 is hydrogen; unsubstituted or substituted, straight-chain or branched, monocyclic or polycyclic, interrupted or uninterrupted C 1 -C 14 alkyl; C 2 -C 14 alkenyl; C 6 -C 10 aryl; C 6 -C 10 aryl-C 1 - C 10 alkyl; or C 5 -C 10 alkyl(C 5 -C 10 aryl); and Dye is a residue of an organic dye, is useful for dyeing of organic materials, such as keratin-containing fibers, wool, leather, silk, cellulose or polyamides.