A nice tool to check your design for color blindness compatibility (e.g. to see whether there is enough contrast for color blinds) is the “Color Oracle” (available for Mac OS, Linux and Windows). In Mac OS, the tool resides on the right side of the menu bar and offers color filters for Deuteranopia, Protonopia and Tritanopia. It even allows you to assign shortcuts to the filter functions: Simply press F5 to view your entire screen instantly in Deuteranopia filter mode.