A spectral sensor comprises (i) a first type of interference filter comprising reflective multilayers of a first type and an intermediate layer configured to give a constructive interference for a wavelength in a first range, and (ii) a second type of interference filter comprising reflective multilayers of a second type and an intermediate layer configured to give a constructive interference for a wavelength in a second range. The sensor further comprises first and second filter stacks configured to selectively transmit light in the first and second wavelength ranges to first and second photo-sensitive areas, respectively. The first filter stack includes the first type of interference filter and a second type of dielectric mirror that is reflective in the second wavelength range. The second filter stack includes the second type of interference filter and a first type of dielectric mirror that is reflective in the first wavelength range.