AboutColorblindness
This phenom known as 'colorblindness' is more common than most people think. In individuals with Northern European ancestry, as many as 8 percent of men and 0.4 percent of women experience congenital color deficiency. What this means, is that almost 9% of people with Northern European ancestry have an inability or impaired ability to see or perceive color differences. Colorblindness tends to be a sex-linked condition, but it can also be caused by physical or chemical damage to the eye (Wikipedia). Affected people are called dichromats because they have only two working cone types, compared to people with normal vision who have three.
Usually classified as a mild disability, it can cause difficulties in everyday life, though exact numbers tend to be under-reported due to a lack of awareness in the general population. These vision deficiencys can affect people all throughout their lives, especially when starting and learning in school, trying to be involved in sports, driving, and restricting what career paths are open for them to explore (Chan).
Invisible Issue
Color EXISTS
Though most people aren't aware of it, the world you see is not the only one that exists. There are at least three major types of color vision deficiencies that effect more people than is generally realized. More information about each type can be found under 'The Trifecta'.