Effect of differential photometry in color–color diagrams. Results are shown for a realization with M_s = 4 and ﹩{\tau }_{g}^{{\rm{h}}}=1.2﹩, assuming the ISRF of MMP83D. The panels are the same as the middle row of Figure 6, except that differential photometry is applied using Equation (7) with τ₀ = 0. The background signal is set to f_diff = 0.2 of the ISRF.