A lighting device comprises a first light source (10) at a first color temperature (Tk1), a second light source (20) at a second color temperature (Tk2) that is different from the first color temperature, and an optical system that forms an illumination spot (3) at an intermediate color temperature (Tkr). The optical system comprises a beam splitter (13) that is arranged to split the light produced by each light source (10, 20) into a transmitted light beam and a reflected light beam. It is arranged to focus said transmitted and reflective light beams (FR1, FR2) and to combine them in a certain superposition configuration in a superposition plane in which said illumination spot is formed, and the optical system and the light sources are arranged to modify the size of the illumination spot (3) at said intermediate temperature.