Method for manufacturing an automotive luminous device, the automotive luminous device being intended to provide a lighting function, wherein the lighting function involves the projection of a light beam with a colour comprised in a predetermined colour range, the automotive luminous device comprising: - a light source comprising a first solid-state substrate and an additional element, the light source being configured to project a light beam with a colour different from the one of the light emitted by the first solid-state substrate, wherein the colour of the light projected by the light source is comprised in the predetermined colour range; - at least one primary optical part (3, 4, 5) configured to receive the light of the light source and to project it outside the luminous device, so that the light projected by the at least one primary optical part has a colour not comprised within the predetermined colour range; - a wavelength conversion layer arranged to modify the colour of the light projected by the at least one primary optical part (3, 4, 5) so that the final beam projected by the luminous device has a colour comprised in the predetermined colour range; the method comprising the steps of: - providing a light source comprising a solid-state substrate and an additional element, the light source being configured to project a light beam with a colour comprised in the predetermined colour range; - providing at least one primary optical part (3, 4, 5) arranged to receive the light of the light source and to project it outside the luminous device; - checking the colour of the light projected by the at least one primary optical part; - choosing and assembling a wavelength conversion layer arranged to modify the colour of the light projected by the at least one primary optical part so that the final beam projected by the luminous device has a colour comprised in the predetermined colour range - wherein the wavelength conversion layer comprises quantum dots. the automotive luminous device comprising: - a light source comprising a first solid-state substrate and an additional element, the light source being configured to project a light beam with a colour different from the one of the light emitted by the first solid-state substrate, wherein the colour of the light projected by the light source is comprised in the predetermined colour range; - at least one primary optical part (3, 4, 5) configured to receive the light of the light source and to project it outside the luminous device, so that the light projected by the at least one primary optical part has a colour not comprised within the predetermined colour range; - a wavelength conversion layer arranged to modify the colour of the light projected by the at least one primary optical part (3, 4, 5) so that the final beam projected by the luminous device has a colour comprised in the predetermined colour range; - a light source comprising a first solid-state substrate and an additional element, the light source being configured to project a light beam with a colour different from the one of the light emitted by the first solid-state substrate, wherein the colour of the light projected by the light source is comprised in the predetermined colour range; - at least one primary optical part (3, 4, 5) configured to receive the light of the light source and to project it outside the luminous device, so that the light projected by the at least one primary optical part has a colour not comprised within the predetermined colour range; - a wavelength conversion layer arranged to modify the colour of the light projected by the at least one primary optical part (3, 4, 5) so that the final beam projected by the luminous device has a colour comprised in the predetermined colour range; the method comprising the steps of: - providing a light source comprising a solid-state substrate and an additional element, the light source being configured to project a light beam with a colour comprised in the predetermined colour range; - providing at least one primary optical part (3, 4, 5) arranged to receive the light of the light source and to project it outside the luminous device; - checking the colour of the light projected by the at least one primary optical part; - choosing and assembling a wavelength conversion layer arranged to modify the colour of the light projected by the at least one primary optical part so that the final beam projected by the luminous device has a colour comprised in the predetermined colour range - wherein the wavelength conversion layer comprises quantum dots. - providing a light source comprising a solid-state substrate and an additional element, the light source being configured to project a light beam with a colour comprised in the predetermined colour range; - providing at least one primary optical part (3, 4, 5) arranged to receive the light of the light source and to project it outside the luminous device; - checking the colour of the light projected by the at least one primary optical part; - choosing and assembling a wavelength conversion layer arranged to modify the colour of the light projected by the at least one primary optical part so that the final beam projected by the luminous device has a colour comprised in the predetermined colour range - wherein the wavelength conversion layer comprises quantum dots.