Before revision:  So far, no theoretical description has been offered to explain the trial-to-trial variability , whereas the sources of the subject-to-subject variability have been associated with individual differences in the properties of the peripheral visual system. Here we explore the role of the Poissonian nature of photon capture on the wavelength-dependence of the trial-to-trial variability in the color matching functions, as well as their correlations .
After revision:  So far, no theoretical description has been offered to explain the trial-to-trial variability , whereas the sources of the subject-to-subject variability have been associated with individual differences in the properties of the responses to color-matching experiments vary with the retinal composition and the wavelengths of peak absorption probability, and compare them with experimental data on subject-to-subject variability obtained previously .