Abstract: To allow environments to be lit with light having characteristics as close as possible to natural light, the appliance (1) comprises a frame (2) supporting pluralities of light sources (5, 6) the light from which is reflected to the outside of the appliance (1) by a reflecting screen (4) via a translucent screen (3). The light sources (5, 6) are of different color temperatures in terms of illumination and are electrically powerable separately via a central control unit (24) in a such a manner as to enable them to provide a luminous flux of variable intensity.