Why Color Accessibility Matters

For individuals with color vision deficiencies, relying solely on color to convey meaning can lead to confusion, misinterpretation, or even danger. Whether you're labeling chemical beakers in a classroom or designing a university website, inclusive color choices ensure that your message reaches everyone — clearly and safely.

Color Contrast

Color contrast ensures objects in the foreground can be distinguished from the background. High contrast is especially important for text color compared to its background. You can use tools to measure the contrast between two color values to determine if they meet accessibility guidelines.

The Web Content Accessibility Guidelines (WCAG) 2.1 defines minimum contrast ratios for normal text, large text and meaningful graphical elements.

WCAG contrast ratios based on content type
Compliance Level Normal Text Large Text* Meaningful Graphical Elements**
WCAG AA 4.5:1 3:1 3:1
WCAG AAA 7:1 4.5:1 N/A

*Large text is defined as either 14+ point (~18.66px) and bold or 18+ point (~24px).
** Elements that a user needs to be able to perceive in order to understand or interact with content are considered “meaningful.”

Contrast Requirements for Logos

Text that is part of a logo or brand name has no minimum contrast requirement. Care should be taken, however, when designing logos for use on Texas A&M websites and when placing logos on various backgrounds.

Tools for Checking Contrast

  • WebAIM Contrast Checker: This tool measures the contrast between two colors and whether or not it meets WCAG contrast standards.
  • WhoCanUse: This tool brings attention and understanding to how color contrast can affect different people with visual impairments.
  • Vispero Colour Contrast Application: Use this free application for Mac and Windows to check color contrast – including text and visual elements.

Don’t Use Color Alone To Convey Meaning

Don’t use color alone to convey meaning. People who use screen readers will not have access to information that is provided through color alone. Additionally, people who are colorblind perceive colors differently. Using color alone to convey meaning assumes everyone perceives colors the same way. It is also recommended that you check your colors using a color blindness simulator to ensure people with color blindness can still perceive your content.

Four different versions of a color-coded speedometer, showing the different shades perceived based on regular vision and three types of color blindness

Red and green are often used to convey meaning, but not everyone can distinguish between these colors. Additionally, when graphics are printed out on a black and white printer, it is impossible to distinguish between the colors.

Use Secondary Indicators in Addition to Color

Quickly and clearly convey meaning to people by combining meaningful color with secondary indicators.

Simple illustration of a table using check marks and x marks to communicate

Icons

Using icons can be a helpful way to provide visual cues about a piece of content. Note: If you are using icons without associated alt text, you will also need to pair them with text labels.

Four validation alerts that use color, icons and text labels to communicate the message

Text Labels

Text labels are helpful in combination with other indicators. The text can be essential for clarity, while other indicators can help with quickly parsing information.

Regular weight black text vs. linked text indicated through font weight, color and underline

Text Styles

Using a variety of styles (bold, italic, etc.) can be a visual indicator that helps convey meaning — such as whether or not something is interactive.

Three versions of a pie chart in solid colors compared to the same charts using patterns

Patterns

Using patterns can be a helpful way to ensure different sections of a chart are distinguishable from each other.

Illustration of a required form field indicated with a red asterisk

Symbols

Sometimes color is used to indicate required fields. Use a symbol, such as an asterisk (*), to add another indicator.

Real World Scenario

Color accessibility applies beyond digital environments. Consider the following example from a chemistry lab.

Students are shown three beakers and told each beaker has a different chemical. Each chemical is a slightly different color: clear, pale yellow and pale pink. For someone with a color deficiency, they may all appear to be the same color. In some cases, picking wrong could have severe consequences. An acceptable alternative for this example would be to clearly label each beaker with a symbol or marker as an additional indicator.

Related Resources

Step-by-step instructions for analyzing Color Contrast

Contrast values can be analyzed using color contrast checkers. Learn how to use them to make content easier to locate and understand.

Keep Learning

Foundational Accessibility Concepts

Learning foundational accessibility concepts will help you create more accessible content regardless of tool or platform.