Abstract: The invention concerns an illumination system for generation of colored, especially amber or red light, comprising a radiation source and a fluorescent material comprising at least one phosphor capable of absorbing a part of light emitted by the radiation source and emitting light of wavelength different from that of the absorbed light; wherein said at least one phosphor is a amber to red emitting a rare earth metal-activated oxonitridoalumosilicate of general formula (Ca1-x-y-zSrxBayMgz)1-n(Al1-a+bBa)Si1-bN3-bOb:Ren, wherein 0?x?1, 0?y?1, 0?z?1, 0?a?1, 0<b?1 and 0.002?n?0.2 and RE is selected from europium(II) and cerium(III).