I was teaching a virtual Camtasia class recently and, while selecting colors for a canvas annotation, we had a robust discussion about colors. Specifically, which colors work for learners who are color blind?
According to Dr. David Nichols, University of Connecticut, approximately "one in 20 people are colorblind in some way."
When someone is colorblind, "one or more of the types of cone cells in the eyes — the cells we use to detect color — does not work normally," said Nichols. "A person who is colorblind sees a reduced color space; two colors which appear distinct to a person with normal color vision may appear to be the same to a person who is colorblind."
Nichols went on to say that "most people who are colorblind have some form of red-green colorblindness, such as deuteranomaly, deuteranopia, or protanopia."
"It can be difficult or impossible to distinguish whether a given color is red or green, and shades of red and green may have very low contrast. Instead of using a color palette of red and green, consider using a similar magenta and green color palette instead," stressed Nichols.
When adding colors to your eLearning projects, Nichols suggests using accessible color palettes. Here is an example as seen on the "Coloring for Colorblindness" website.