Not everyone sees the same shade of red apples, blue sky, or green grass. Colorblindness is quite common and with the condition being invisible to others, it’s easy to forget that many of our family, friends, and coworkers are viewing the world in very different ways. Being colorblind is completely normal and it usually does not negatively affect any day-to-day activities. When we’re aware that people have different forms of color vision, we can be thoughtful about presenting information that relies on color alone to convey meaning.

There are different types of colorblindness, each possible to have to various degrees. The most common type is red-green varieties that make it difficult to distinguish between those two colors. These are called Protanopia and Deuteranopia when in the higher degrees and Protanomaly and Deuteranomaly for lesser degrees. You may wonder how people can understand traffic signals that rely on red and green lights. This is because every traffic light also follows a consistent order so there is a secondary way to distinguish between stop, caution, and go.

This photo simulates how a person with red-green colorblindness may view traffic lights.

Another type of colorblindness is blue-yellow or Tritanopia or Tritanomaly in which only the red and the green cone pigments are present. With a total absence of blue retinal receptors, blues appear green, yellows and oranges appear pink, and purple colors appear deep red.

Photo split diagonally to simulate Tritanopia vision vs full-color vision on an assortment of fruit and vegetables.

It is much rarer, but not impossible, to have no color vision at all. Achromatopsia is like watching the world as a classic black and white film. People with Achromatomaly vision see less vibrant hues of all colors.

Split photo showing Achromatopsia vision vs full-color vision using a taxis on a city street.

When designing something for the web or print, try turning your work to grayscale to make sure the content can still be read and understood. Don’t use color alone to distinguish an element that conveys meaning or information. Other ways to distinguish something could be to add a pattern or texture as well as color. Also, don’t use color to give instructions in your content. For example: instead of clicking the “red” button, try “cancel” or be more specific about the action you want the user to take.