Example of parameter selection based on predicted color distributions in the CIELAB color space. The a* and b* axes represent chromaticity coordinates, while the shaded blue polygon denotes the color gamut already obtained without adding new parameters. The colored ellipses (red for $P_1$, green for $P_2$, and purple for $P_3$) indicate the 95% confidence regions of the predicted color positions, showing where the resulting color is most likely to lie for each parameter. Dots within the ellipses represent individual simulated color coordinates, and the black-edged circles correspond to the mean predicted color for each parameter. The outer black line represents the current achievable gamut, while the green and purple outlines illustrate possible extensions of the gamut if the actual color corresponds to predicted points outside the existing region. This example suggests that $P_2$ is the most promising choice (most likely to expand the gamut), followed by $P_3$ (large uncertainty) and $P_1$ (unlikely to expand the gamut).