A process and a kit-of-parts for dyeing keratinous material such as human hair are provided. An exemplary process includes applying an agent (a) to the keratinous material. The agent (a) includes (a1) at least one organic silicon compound. The method further includes applying an agent (b) to the keratinous material. The agent (b) includes (b1) at least one coloring compound comprising at least one effect pigment comprising a substrate platelet and a coating. The coating includes at least one layer wet-chemically prepared using a metal alkoxide and an organosilicon compound having a basic group. The agent (b) further includes (b2) at least one film-forming polymer.