Don't rely on color to convey your message

Color should be used as an enhancement, not as the primary means of communicating. To make sure everyone can read and understand your documents, never rely on color alone to transmit information. This does not mean that you cannot use color, but rather that if you choose to use color, the content’s meaning would not change in the absence of the color. For example, if you are requiring that a field be filled in on a form, include the word "Required" rather than just making the required field red.

Facts on Color Blindness:

• Most color blind people are not really color “blind” but are instead color deficient.
• Color blindness is more prevalent among males because the most common form is caused by a deficiency in the X chromosome.
• 8% of men suffer from a form of color blindness.
• Deuteranopia is by far the most common form of colorblindness, and it affects the vision of red and green
  colors.

Pale Blue

As eyes age, the first color that people notice a degradation in is pale blue. This happens because the cones in your retinas that detect color start to lose some of their sensitivity with age, and there is not a lot that can be done about it. A large segment of the population may find it difficult to read documents with pale blue text color.

Why does color contrast matter?

If text does not have sufficient contrast with its background, it can be difficult to read, and this certainly does not apply only to those who have a vision impairment. Anyone viewing content in less-than-ideal conditions, such as with a poor monitor, reflections, or glare, may not be able to view the text or may have difficulty viewing it.

Using a Contrast Checker

WebAIM’s free contrast checker on their website verifies that the colors in a document provide enough contrast to be viewable by a larger audience. If you have questions regarding color contrast, please reference the WebAIM website.

To meet the WCAG 2.1 AA standard, 

Laser Pens and Color Blindness in Presentations

Laser pens are often used in presentations to highlight a particular area of the slide. The most common colors of laser pens are red and green, which happen to be the two colors that affect people the most with color blindness. A color-blind person may find a red/green dot difficult to track on the screen. Instead, they may see a dull gray dot that can easily blend in with the rest of your presentation.

Tips for using laser pens:

• Hold the pen still on the screen
• Move it slowly
• Speak what you are showing. Do not simply say “here” or “over there.” Instead, say, “on the left side of the screen towards the top."