....; 206, 207), each of said light-emitting diodes emitting, in operation, visible light in a preselected wavelength range, so forming two primary light sources, wherein the emitted wavelengths of at least two light-emitting diodes (6, 6', ..., 7, 7', ...; 106, 106', ..., 107, 107', ...; 206, 207) are different, characterized in that the lighting system (1; 101; 201) includes conversion means (10; 110...