Disclosed herein is a composition comprising at least one fluorescent dye and at least one insoluble polyorganosiloxane conditioning polymer, processes using this composition, and a device.Further disclosed herein is the use of compositions comprising at least one fluorescent dye and at least one insoluble polyorganosiloxane conditioning polymer, for dyeing human keratin materials, for example artificially dyed and/or pigmented hair and dark skin, with a tightening effect.