Color blindness (or colour blindness — or more specific color vision deficiency (CVD)) is well known but hard to imagine if you are not suffering from it. So usually people are either looking for more information to learn about color blindness and all its details, would like to better understand the vision by simulating it or want to test themselves with some form of color blindness test. All this you can be found here on color-blindness.com — and much more.