A flat lamp has a large area of light radiation with optic fiber bodies (1) for rear lighting of one or more light exit surfaces. The lamp is equipped with a number of light sources (2) whose light with at least two different colors is fed into the light-entry regions of the optic fiber bodies, to be mixed there. Each light body possesses at least as many light- entry surfaces as different colors provided for mixing. To each light-entry surface is assigned a certain color. The light sources are screened against light radiation in other regions than the light-entry surfaces of the optic fiber bodies.
