The authors tested the validity of the theory experimentally using a few diffusing multilayers, each consisting of three distinct layers, as samples. The reflectances of each layer with (R) and without (R0) itself as its backing layer were separately measured for different wavelengths under identical conditions of illumination and measurement. After conversion of the relative values of R and R0 into absolute ones, it was possible to calculate the matrix elements of each layer and hence those of the multilayered samples. From those matrix elements, the reflectances of the multilayered samples could be calculated for different wavelengths. Also, the spectral reflectances of the multilayers as such were measured in the manner indicated. Comparison of the calculated reflectance vs. wavelength curves with experimental ones for the multilayered sample demonstrated good agreement between the theory and the experimental results within the limits of experimental accuracy.