The present invention provides a system and method for generating light using light-emitting elements and detecting the intensity and spectral power distribution of light using the same light-emitting elements as spectrally sensitive photodetectors. The light-emitting elements function in two modes, an ON mode and an OFF mode, wherein in the ON mode the light-emitting elements are activated and emit light of a particular frequency or range of frequencies. When in the OFF mode, the light-emitting elements are deactivated, wherein they do not emit light but serve to detect photons incident upon them thus generating an electrical signal representative of the intensity and spectral power distribution of the incident photons. The detected signal from the deactivated light-emitting elements can be used to provide photonic feedback to a lighting system, and thereby may be used to control the brightness and color balance of the lighting system. In addition, the light-emitting elements may be arranged such that no spectrally selective filters or optics are necessary to block or focus light onto the light-emitting elements when in the detection or OFF mode.