Standard deviation (solid lines) and maximum difference (dashed lines) in K_S − W₁ (black) and W₁ − I₁ (red) colors as a function of the peak optical depth of the 3 μm feature, calculated for five absorption profiles (see Fig. 4). The K_S − W₁ color is significantly more sensitive to variations in the absorption profile, while W₁ − I₁ remains comparatively stable, enabling robust measurements of ${\tau }_{3.0}^{max}$.