Detectability of color-coded toilet signs

Abstract

In the previous paper we reported colors to represent male （5PB4/12） and female（7.5RP5/14） that were obtained from 100 Thai subjects. We then experimented to see if colored sign is better than achromatic sign to detect from far distances. Achromatic signs for male and female figures and chromatic signs, blue male and the red female. Those signs were presented at different 11 viewing distances in the outdoor, from 35 m to 250 m, and subjects responded which sign they recognized by naked eyes and wearing the cataract experiencing goggles. The red sign gave the longest viewing distance. The blue sign appeared black at far distances and gave a similar result as the achromatic black sign.