9-12% of men have some form of color blindness. When producing visualizations, it can be useful to simulate what the colors used in your visualizations look like to people with various types of color blindness. The two that I use are Color Oracle and Sim Daltonism.

Color Oracle is available for Windows, Mac, and Linux. I have only used the Mac version, but it works well: select the color blindness type you want to simulate from the menubar and it temporarily shows a simulated version of your display. It can simulate deuteranopia, protanopia, tritanopia.

Sim Daltonism is for the Mac only. It can simulate more types of color blindness than Color Oracle. It works by creating a new window which shows the area around the mouse with the selected type of color blindness. This is more useful for interactive visualizations.

There are also online tools available if you don’t want to install any software: Vischeck can convert images or URLs.