Lighting system for an exterior trim part of a motor vehicle, having at least • a configuration region, which has a visible side facing towards the outer side and a rear side with a rear-side face as well as side faces, the configuration region in the form of a light-guide body consisting of a transparent thermoplastic material which is suitable for laser engraving, preferably a PMMA, the configuration region forming a light window and being processed by means of a laser structure on the rear-side face or by means of local structures inside the configuration region for individual adaptation of the vehicle and/or for representation of a characteristic feature appearing three-dimensionally on the visible side, • a housing element which has a trough-shaped recess with a bottom face and side faces, • wherein the configuration region is attached to the housing element in such a way that the configuration region is enclosed at least by a rear-side section of the recess and an air gap remains between the rear-side face of the configuration region and the bottom face, and that an installation space remains between at least one side face of the configuration region and one side face of the housing element, • wherein at least one light source is arranged in the at least one installation space, the light being couplable into at least one side face of the configuration region and being outcouplable in the further beam path at the laser structure or at the local structures and subsequently being radiated through the configuration region on the outer side in order to generate the three-dimensional characteristic feature, • wherein the at least one light source in the installation space is covered by a colouring coating, characterized • in that the bottom face of the housing element is provided with a second colouring coating, • and in that the configuration region is in the form of a cover element which has the configuration region in the form of the at least one light window and at least one opaque section with the first colouring coating, wherein this opaque section covers the light source in the installation space from the visible side, • and in that the first colouring coating of the cover element and the second colouring coating of the bottom face of the housing element are designed with the same colour, preferably the car colour. • a configuration region, which has a visible side facing towards the outer side and a rear side with a rear-side face as well as side faces, the configuration region in the form of a light-guide body consisting of a transparent thermoplastic material which is suitable for laser engraving, preferably a PMMA, the configuration region forming a light window and being processed by means of a laser structure on the rear-side face or by means of local structures inside the configuration region for individual adaptation of the vehicle and/or for representation of a characteristic feature appearing three-dimensionally on the visible side, • a housing element which has a trough-shaped recess with a bottom face and side faces, • wherein the configuration region is attached to the housing element in such a way that the configuration region is enclosed at least by a rear-side section of the recess and an air gap remains between the rear-side face of the configuration region and the bottom face, and that an installation space remains between at least one side face of the configuration region and one side face of the housing element, • wherein at least one light source is arranged in the at least one installation space, the light being couplable into at least one side face of the configuration region and being outcouplable in the further beam path at the laser structure or at the local structures and subsequently being radiated through the configuration region on the outer side in order to generate the three-dimensional characteristic feature, • wherein the at least one light source in the installation space is covered by a colouring coating, characterized • in that the bottom face of the housing element is provided with a second colouring coating, • and in that the configuration region is in the form of a cover element which has the configuration region in the form of the at least one light window and at least one opaque section with the first colouring coating, wherein this opaque section covers the light source in the installation space from the visible side, • and in that the first colouring coating of the cover element and the second colouring coating of the bottom face of the housing element are designed with the same colour, preferably the car colour.