Disclosed herein is an effect pigment having a layer stack which comprises a highly reflective metallic flake having a first major interface and opposed to this first interface a second major interface, and at least one side surface and directly adjacent on one or of both of these major interfaces a layer of a semiconducting material having an average atomic composition of: a) Si.sub.(1-x)Sn.sub.x, wherein 0<x<0.90 or b) Ge.sub.(1-y)Sn.sub.y, wherein 0<y0.80 or c) Si.sub.(1-m-n)Ge.sub.mSn.sub.n, wherein 0<m<1.00, 0<n<1.00 and with the proviso that m+n<1.00.

The process of coloring keratinous material comprising the use of an organosilicon compound, an effect pigment, and a sealing reagent VI Provided herein is a process for dyeing keratinous material, in particular human hair, comprising the following steps: Application of an agent (a) to the keratinous material, wherein the agent (a) comprises: (a1) at least one organic silicon compound selected from the group of silanes having one, two or three silicon atoms, and (a2) at least one colorant compound comprising at least one substrate platelet-based pigment comprising a lamellar substrate pigment, and Application of an agent (b) to the keratinous material, wherein the agent (b) comprises: (b1) at least one sealing reagent.

A composite powder according to an embodiment of the present disclosure has excellent UV blocking effect. The composite powder includes an ultraviolet ray-blocking coating layer containing ZnO on the surface of the plate-shaped substrate containing TiO.sub.2, thereby enabling the blocking of ultraviolet rays in the UVA and UVB regions, and is also expected to block fine dust through treatment with a silane compound or a silica compound.