We introduce a so-called "mean-path-defined Yule-Nielsen" (MPD-YN) model for predicting the color of halftone prints in reflectance or transmittance modes, inspired by the Yule-Nielsen modified spectral Neugebauer model, where the empirical n value is replaced with a spectral parameter different for each halftone, directly calculated thanks to a closed-form formula, a function of the measured spectral reflectances (or accordingly transmittances) of full-tone calibration patches and the surface coverages of the Neugebauer primaries in the halftone. This parameter is based on the average number of internal reflections undergone by light between two half layers of the print, whose expression derives from a flux transfer model between the two half layers. According to the tests carried out in this study with paper printed in inkjet, the predictive performances of the MPD-YN model are rather good and very close to those obtained with the Yule-Nielsen model.