A plurality of cellular concave mirror surfaces are formed on a plate-like reflector unit, and a plurality of light-emitting diodes are disposed on these cellular concave mirror surfaces to jointly form a colored light source. Connection wirings to be connected with a power supply source are provided on a substrate laminated with the reflector unit. A lamp base of a conventional type may be coupled to the substrate for being electrically connected to the wirings. This colored light source can provide a single or multiple color displays. Improved shadow pattern display can be provided by forming a complementary color pattern on a front cover lens. Letter, symbol or pattern display can be provided by selectively arranging light-emitting diodes on the reflector unit. In case the above-mentioned light source is used as a traffic signal device, power dissipation and maintenance care are reduced by the light-emitting diodes having low power consumption and long service life, and high security of the traffic is assured by the elimination of false indications caused by external lights.