Metamerism and Color Inconstancy for Spot Color Printing
By Awadhoot Shendye
The use of metamerism index and color inconstancy index were studied for approval of spot colors used in decorative gravure products, especially spot colors, which are viewed under different light sources at the customer’s end. This work shows that the metamerism index is not sufficient for approval of spot colors, because it doesn’t provide any idea about how colors will transform under different light sources. Color inconstancy index makes use of chromatic adaptation transforms to assess the effect of the change in light source, and thus, it helps in selection of a spot color and, at the same time, reduces color-engineering problems in color reproductions.