Assistive Technology

Color Matters in Accessibility

Color blindness makes it hard to tell the difference between certain colors. It affects between 1 in 12 men and 1 in 200 women and approximately 300 million people worldwide (about the same number as the entire population of the United States). There are several types of color blindness. (See the list to the right for the most common types.)

Here are some examples of the way those with color blindness might see color.

Deuteranopes

People with deuteranopia can’t distinguish green colors, making it one subtype of what’s commonly called “red-green colorblindness”. Deuteranopes can exhibit a nearly complete blindness to green or a lack of sensitivity to green hues

Protanopia

Protanopia is a condition where people can’t distinguish red hues, and it’s the other subtype of red-green colorblindness.

Tritanopia

What can you do to ensure your use of color doesn’t negatively impact those with color blindness?

1. Use high contrast colors (dark on light or light on dark) for text. Black will always be the best option.

2. Don’t create things that are color dependent for other people. Label everything. For example, if you say all of the items in blue are due on Tuesday, a student may not be able to see what is blue and what is not. Don’t depend on color for electrical wiring, label the wires.

3. Don’t use text on top of images, it may blend in and become lost in the picture.

4. Provide bright or natural lighting - this helps distinguish subtle changes and make it easier to distinguish between colors.

5. Ask - It is okay to ask to ensure everyone in your class can see when you use color. Rather than singling out a person who is color blind, you can simply ask, “does this color work for everyone?”

Websites:

This Color Blindness Simulator allows you to add an image and look at it from each type of color blindness.

This Contrast Checker will help you determine if the text color you use has enough contrast.

Tritanopia is a form of color blindness where a person can’t tell the difference between blue and yellow.

Monochromacy

The most rare type of color blindness, see everything in shades of grey.

The information in this article is from the Color Blindness Awareness website.

https:// www.colourblindawareness.org

/colour-blindness/types-ofcolour-blindness/