Most of us have “normal” color vision. For those of us who like to dress for conspicuity or visibility, we judge the visibility of our clothing based on our vision. About seven to eight percent of the male population in Western nations, however, are color blind to some degree. Is your blaze orange hunting vest as visible as you think it is?
Dartmouth University engineer professor and cyclist Charlie Sullivan asked the question and, with the help of software from Vischeck which simulates the effects of color blindness on images, he came to some interesting conclusions. The high viz yellow now favored by many bike commuters indeed remains highly visible to the colorblind, but it turns out bright blue also provides a good amount of contrast. Some other fluorescent colors such as hot pink, on the other hand, fade out when run through the colorblind filter.
For more interesting information about colorblindness and how it effects you as a cyclist, visit Colors for Daytime Cycling Visibility: Effect of Color Blindness. Although it’s a little dated, there’s also some information about how visible red LEDs are to some colorblind people.