Appropriate color use plays a major role in creating accessible digital content. Because color is often used to convey meaning—such as to highlight, organize, or differentiate—it’s important to ensure that information communicated through color is also perceivable by users with color vision disabilities.
Color and Low Vision Disabilities
Color vision deficiencies (commonly referred to as color blindness) are most often inherited but may also result from age-related visual changes or the side effects of certain medications.
Note: The video above was produced in 2013. Data shared in the video may differ from figures included in the following sections.
Consider the following facts about vision-related disabilities:
- Approximately 7.08 million people in the United States experience visual acuity loss (low vision), which is about 2.2% of the population, and around 1.08 million people are considered blind (approximately 0.3% of the population).
- Around 8% of men and 0.5% of women worldwide have some form of color vision deficiency (color blindness). The often-cited range of 7% to 12% for men accounts for variations across different ethnic groups and populations, as prevalence rates differ globally.
- The prevalence of low-vision conditions increases with age. According to Johns Hopkins Medicine:
- Less than 1% at age 45
- Almost 5% at age 75
- Nearly 15% at age 85
Types of color-vision disabilities include:
- Deuteranopia: reduced sensitivity to green light (i.e., unable to perceive green)
- Protanopia: reduced sensitivity to red light (i.e., unable to perceive red)
- Tritanopia: reduced sensitivity to blue light (i.e., unable to perceive blue and yellow)
- Achromatopsia: complete inability to perceive any color (rare)
- People with monochromacy perceive the visual world in shades of gray
Given the prevalence of color vision and low-vision conditions, it’s important to use color in a way that includes everyone. If color is chosen carelessly, for example, by using hard-to-read color combinations or relying only on color to show meaning, it can make your content confusing or unreadable. This doesn’t just affect people with diagnosed vision disabilities. Even users with typical vision can struggle to read content when there’s not enough contrast, the colors are too similar, or the text is too small, which can lead to eye strain, frustration, or missed information.
Examples of How Color-Vision Disabilities Affect Perception
Below are examples of how the same image, the CSU Channel Islands logo in black, red, and grey, may appear to individuals with different types of color-vision disabilities. These simulations illustrate how certain colors can become indistinguishable depending on the type of vision condition. This is why it’s important not to rely on color alone to convey meaning.
Making Color Use Accessible
Color can enhance clarity and engagement, but it must be used intentionally and with accessibility in mind. Whenever color is used to convey meaning, such as in charts, navigation cues, or status indicators, it should be paired with another visual cue (i.e., labels, patterns, or symbols) or a clear explanation of its meaning.
Color Use Considerations for Accessibility
- Do not rely on color alone to communicate essential information. Provide text labels, patterns, shapes, or icons as additional visual indicators.
- Pair color with symbols or shapes when presenting data, alerts, or categories (e.g., a red circle with an exclamation point, not just a red highlight).
- Avoid using red, green, or colors heavy in red-green hues to convey meaning, as these can be difficult to distinguish for users with deuteranopia or protanopia.
- Avoid red text on black backgrounds or black text on red backgrounds; this combination can appear unreadable to those who cannot perceive red tones.
- Maintain strong color contrast between text and background to support overall readability (see previous section on color contrast).
Note: This list highlights only a few key considerations and is not comprehensive. Continually evaluate your specific content and context to ensure color use supports accessibility for all users. These considerations are provided to help you make informed, inclusive decisions when using color in your digital content.
