Color-blind people are using your apps. 1 in 12 men is color blind. And for women, this is 1 in 200. Building apps that work well for color blind people is not difficult. Some simple techniques help us with the design of our interface. And some tools help us see what color blind people see. In this talk, Maarten Arts of Avisi will look at common varieties of color blindness. We will look at apps through the eyes of a color-blind person. And we will discover what color-blind people struggle with. Regardless of whether you're a designer or developer, this talk will equip you with the skills and the tools you need to make sure that your app works for color-blind people.