Chemical sensor based on the colorimetric response of porous silicon photonic crystal

•The colorimetric response of porous Si photonic crystals to the liquid analytes was analyzed.•The colorimetric parameters are preferable for characterization of the kinetics of complex spectra.•The colorimetric sensitivity is larger for sensors with higher porosity of bi-layers.•The colorimetric sensitivity increases for sensors with peak position in short wavelength region.•The colorimetric based parameters were compared with traditional Bragg peak parameters.