Color and Contrast
If using color alone to convey meaning, be sure to also supplement a text description so that users with visual barriers can also access that information. Below is an example of a table that uses incorrect usage of color:
Instead use text with color to give context. The example below, shows correct usage of color:
In addition, the Microsoft Excel sheet must have a sufficient contrast ratio for foreground and background. A minimum contrast ratio of 4:5:1 for regular text or 3:1 for large print is required*.
*Note: Large print is considered to be a font size of 18pt font or 14pt bold font.
To evaluate color contrast, you can download and install the Colour Contrast Analyzer. Using the Colour Contrast Analyzer software, click the foreground eyedropper icon and drag the cursor over foreground, then click the background eyedropper icon and drag the cursor over the background. This will determine the contrast ratio between foreground and background content.
Check that the color contrast ratio passes the minimum requirements (WCAG 2.1 - 1.4.3 Contrast (AA)). Repeat this process for each element in your document.
Reference: Contrast and Color Accessibility by WebAIM.
