Left panel: ﹩{(g-I)}_{0}﹩ vs. ﹩{(g-i)}_{0}﹩ for clusters in NGC 5128. Middle panel: ﹩{(g-I)}_{0}﹩ vs. ﹩{(g-z)}_{0}﹩ for the same clusters. Right panel: ﹩{(g-I)}_{0}﹩ vs. [Fe/H] for the same clusters. The equations for the interpolation lines are given in the text: in the right panel, the solid line is Equation (1) in the text.