A light source including: a light unit including multiple emitting diodes, LEDs; a light transmissive light guide having an input end, an output end, and a central region therebetween, the light guide extending along an axial direction, the light transmissive light guide comprising: a reflector being arranged adjacent to the output end of the light transmissive light guide; wherein: the light unit is arranged adjacent to the input end for injecting light into the central region; the light guide is arranged such that its index of refraction is higher than the index of refraction of the medium exterior to the light guide; the reflector comprises a reflecting surface facing the output end and covering at least a portion of the output end; and wherein: the reflecting surface is arranged such that at least a portion of the reflecting surface is one of concave and convex; and characterized in that the reflector comprises at least one transmitting portion that is not covered with the reflecting surface, arranged so as to transmit light incident on the at least one transmitting portion through the reflector; and the light guide comprises a color mixing rod extending along the axial direction, wherein the color mixing rod comprises at least a portion of the central region, the color mixing rod being arranged for mixing light from the multiple LEDs in the light unit. a light unit including multiple emitting diodes, LEDs; a light transmissive light guide having an input end, an output end, and a central region therebetween, the light guide extending along an axial direction, the light transmissive light guide comprising: a reflector being arranged adjacent to the output end of the light transmissive light guide; wherein: the light unit is arranged adjacent to the input end for injecting light into the central region; the light guide is arranged such that its index of refraction is higher than the index of refraction of the medium exterior to the light guide; the reflector comprises a reflecting surface facing the output end and covering at least a portion of the output end; and wherein: the reflecting surface is arranged such that at least a portion of the reflecting surface is one of concave and convex; and characterized in that the reflector comprises at least one transmitting portion that is not covered with the reflecting surface, arranged so as to transmit light incident on the at least one transmitting portion through the reflector; and the light guide comprises a color mixing rod extending along the axial direction, wherein the color mixing rod comprises at least a portion of the central region, the color mixing rod being arranged for mixing light from the multiple LEDs in the light unit. a reflector being arranged adjacent to the output end of the light transmissive light guide; wherein: the light unit is arranged adjacent to the input end for injecting light into the central region; the light guide is arranged such that its index of refraction is higher than the index of refraction of the medium exterior to the light guide; the reflector comprises a reflecting surface facing the output end and covering at least a portion of the output end; and wherein: the reflecting surface is arranged such that at least a portion of the reflecting surface is one of concave and convex; and characterized in that the reflector comprises at least one transmitting portion that is not covered with the reflecting surface, arranged so as to transmit light incident on the at least one transmitting portion through the reflector; and the light guide comprises a color mixing rod extending along the axial direction, wherein the color mixing rod comprises at least a portion of the central region, the color mixing rod being arranged for mixing light from the multiple LEDs in the light unit. the light unit is arranged adjacent to the input end for injecting light into the central region; the light guide is arranged such that its index of refraction is higher than the index of refraction of the medium exterior to the light guide; the reflector comprises a reflecting surface facing the output end and covering at least a portion of the output end; and wherein: the reflecting surface is arranged such that at least a portion of the reflecting surface is one of concave and convex; and characterized in that the reflector comprises at least one transmitting portion that is not covered with the reflecting surface, arranged so as to transmit light incident on the at least one transmitting portion through the reflector; and the light guide comprises a color mixing rod extending along the axial direction, wherein the color mixing rod comprises at least a portion of the central region, the color mixing rod being arranged for mixing light from the multiple LEDs in the light unit. the reflecting surface is arranged such that at least a portion of the reflecting surface is one of concave and convex; and characterized in that the reflector comprises at least one transmitting portion that is not covered with the reflecting surface, arranged so as to transmit light incident on the at least one transmitting portion through the reflector; and the light guide comprises a color mixing rod extending along the axial direction, wherein the color mixing rod comprises at least a portion of the central region, the color mixing rod being arranged for mixing light from the multiple LEDs in the light unit.