A light source apparatus (310) includes a first (301), second (302) and third (303) light source each configured to generate a different color light beam; a beam combining element (305) having a first incident surface (311) directed to the first light source (301), a second incident surface (312) directed to the second light source (302), a third incident surface (313) directed to the third light source (303) and an emergent surface (314); and a first lenslet array (331) placed on the first incident surface (311), a second lenslet array (332) placed on the second incident surface (312) and a third lenslet array (333) placed on the third incident surface (313) of the beam combining element (305), wherein the beam combining element (305) is configured to combine the light beams from the first (301), second (302) and third (303) light sources into a mixed-color light beam and to emit the mixed-color light beam from the emergent surface (314).