Color Universal Design -Analysis of Color Category Dependency on Color Vision Type (4)-

摘要

This report is a follow-up to SPIE-IS&T / Vol. 7528 75280-1-8, SPIE-IS&T / Vol. 7866 78660J-1-8 and SPIE-IS&T / Vol. 8292 829206-1-8. Colors are used to communicate information in various situations, not just for design and apparel. However, visual information given only by color may be perceived differently by individuals with different color vision types. Human color vision is non-uniform and the variation in most cases is genetically linked to L-cones and M-cones. Therefore, color appearance is not the same for all color vision types. Color Universal Design is an easy-to-understand system that was created to convey color-coded information accurately to most people, taking color vision types into consideration. In the present research, we studied trichromat (C-type), protan (P-type), and deutan (D-type) forms of color vision. We here report the result of two experiments. The first was the validation of the confusion colors using the color chart on CIELAB uniform color space. We made an experimental color chart (total of color cells is 622, the color difference between color cells is 2.5) for this experiment, and subjects have P-type or D-type color vision. From the data we were able to determine "the limits with high probability of confusion" and "the limits with possible confusion" around various basing points. The direction of the former matched with the theoretical confusion locus, but the range did not extend across the entire a* range. The latter formed a belt-like zone above and below the theoretical confusion locus. This way we re-analyzed a part of the theoretical confusion locus suggested by Pitt-Judd. The second was an experiment in color classification of the subjects with C-type, P-type, or D-type color vision. The color caps of the 100 Hue Test were classified into seven categories for each color vision type. The common and different points of color sensation were compared for each color vision type, and we were able to find a group of color caps that people with C-, P-, and D-types could all recognize as distinguishable color categories. The result could be used as the basis of a color scheme for future Color Universal Design.