In one embodiment, a method includes receiving outputs from multiple photodetectors, calculating a first ratio between first and second such outputs, calculating a second ratio between the first output and a difference corresponding to a flicker noise component obtained from the second output, and determining a contribution from multiple illumination types based at least in part on the first and second ratios. The method may also include obtaining multiple correction coefficients based at least in part on the determined contribution, and in turn determining an ambient light type present in proximity to the photodetectors using the correction coefficients and the first and second outputs.