Integrated residuals (observed minus best model and calculated assuming bidimensional Gaussian distributions for each individual point) for (top) F438W vs. F336W, (middle) F438W vs. E(4405 − 5495), and (bottom) F438W vs. R₅₄₉₅ in experiments 1 and 3. The results for experiment 1 are shown as black and white contour plots and are the result of integrating the data in Fig. 2 (note that a slightly smaller range of magnitudes is shown here). The results for experiment 3 are shown as color-filled density diagrams. The three small squares in the top panel mark the centers of the distributions for experiments 1 and 3 and for the ideal solution. The dotted lines in the bottom panels are the linear fits to the residuals for experiments 1 and 3 and the ideal solution.