An article I was reading in this week’s Economist magazine reminded me of Color Oracle, the software Bernhard Jenny (Swiss Institute of Cartography, ETH Zurich) developed to silence my continual prodding after listening to Cynthia Brewer talk about color blindness (color vision impairment) at a NACIS conference in 2000 (?!). It struck me there should be a tool that actually allowed the designer to see what their design looked like to someone with this impairment and not just try to make something work using limited “blessed” color combinations. An earlier effort produced Sim Daltonism, a Mac only tool that does a similar job as Color Oracle.
Color Oracle takes the guesswork out of designing for color blindness by showing you in real time what people with common color vision impairments will see. Color Oracle applies a full screen color filter to art you are designing – independently of the software that you are using. Eight percent of all males are affected by color vision impairment and it’s good to make sure that your graphical work is readable by the widest possible audience. This software is free and works on Mac, Windows, and even Linux. Get it here.
Back to the Economist graphic on real prefectural spending per person in Japan This graphic uses a divergent color scheme that is convenient for most readers, but hard to read for others. The strong hue contrast between the red and green segments of the legend’s color ramp becomes hard to distinguish for people with color vision impairment (see 2nd image past the jump for simulated view using Color Oracle).