Contrast Matters: Determining Inclusive Color Choices of Text

Introduction to color contrast as defined by WCAG and how contrast between text and background directly affects readability across slides, documents, Canvas pages, and other instructional materials. Sufficient contrast is a core accessibility requirement that ensures text is perceivable for students with low vision, age-related vision changes, or color-vision deficiencies, while also benefiting all learners by reducing eye strain and supporting comprehension.

Ensuring Readable and Inclusive Content in Teaching Materials

What is it?

Color contrast is the difference between text and background color and sets expectations for how faculty use color in Canvas so that instructional content is easy to use and read.

1.4.3 Contrast (Minimum) - Level AA

The visual presentation of text and images of text has a contrast ratio of at least 4.5:1, except for large-scale text that have a contrast ratio of at least 3:1.

Why it is important?

Sufficient color contrast is a core accessibility requirement that ensures text is perceivable and readable for all learners. Students with low vision, age-related vision changes, or color-vision deficiencies may be unable to read content that lacks adequate contrast, but poor contrast also negatively affects students without diagnosed disabilities by increasing eye strain and slowing comprehension. Many screen reader users rely on partial vision, magnification, or a combination of audio and visual access, making readable text essential even when assistive technology is used. On mobile devices, small screens and variable lighting conditions further magnify contrast problems, and colors that appear readable on a desktop may fail on a phone or tablet. WCAG establishes minimum contrast ratios (4.5:1 for normal text and 3:1 for large text) to promote consistent, usable content across platforms. Designing with strong contrast from the start improves readability in online, mobile, and printed formats, reduces cognitive load, and supports equitable access to course materials for the widest possible range of students.

How do I do it in Canvas?

Do

• Use default text color at all times.
• Use built-in features from RCE ribbon for headings (H2–H4), lists, and spacing to create structure.

Use sparingly

• Bold for brief emphasis — not entire sentences or paragraphs.
• Italics for foreign words and bibliographic titles.
• Highlighting only in grading or feedback contexts when marking specific student work.

Don’t

• Do not use colored text for emphasis, organization, or design.
• Do not use text highlighting in course content (often fails contrast requirements, relies only on visual cues, renders inconsistently across devices, and is not conveyed by screen readers).
• Do not place text over images.