Color Contrast in Microsoft Excel

Overview

This article describes how to assess color contrast for Excel workbooks.

Key Best Practices for Excel Color Contrast

• Don't rely on color alone to convey meaning. Use text labels, patterns, or icons with alternative text.
• Avoid images of text in Excel—use actual text in cells instead.
• Use high-contrast color combinations for data and headers.
• Use a pre-defined Excel theme that you know to have good contrast ratios. Most pre-defined themes have good contrast ratios, but you can use techniques described below to evaluate them if you have doubt. 

Following are the minimum contrast ratios defined by the WCAG 2.2 standard. 

Using Excel Accessibility Assistant to Check Color Contrast in Excel

Note: At this time, Accessibility Assistant does not appear to reliably assess color contrast in charts or table heading. If you have any doubt about the color contrast of the theme you're using, you can use one of the following methods to assess color contrast.

How to Assess Color Contrast in Excel Using WebAIM Color Contrast Checker (Without Using AXE Assistant - no login required)

The following process will allow you to test arbitrary colors without needing a Deque login. It depends on the WebAIM Color Contrast Checker. This manual method can be much faster and more interactive than the machine learning (AI) method discussed in the next section.

Step 1: Identify the Colors

1. Select the cell with the text you want to check
2. Note the font color (display the Home tab, then click the Font Color dropdown)
3. Get the hex values or RGB values of the text color
4. Note the fill/background color (display the Home tab, then click Fill Color dropdown)
5. Get the hex values or RGB values of the background color

Step 2: Use a Color Contrast Checker Tool

Since Excel doesn't have a built-in contrast checker, use an external tool. This example uses the WebAIM Color Contrast Checker.

1. Browse the the tool you wish to use.
2. Enter the foreground and background texts. 

Using AXE Assistant at Deque University (login credentials required)

The AXE Assistant is a machine learning system trained on Deque content. It is available to authenticated Deque customers, including users of Deque University. (Digital Accessibility Training through Deque University)

1. Browse to the AXE Assistant at Deque University. (You will be required to log in.)
2. In the Ask AXE Assistant prompt field, ask for the contrast ratio you want to check. For example, "what is the contrast ratio of [foreground color] text against [background color] background?" or "Does [foreground color] colored text against [background color] background color provide enough contrast to conform to WCAG?" (You should use either hex codes, RGB codes, or standard HTML color names.)
3. AXE Assistant will typically return an assessment of how well the contrast ratio conforms to the current WCAG standard. It may also make suggestions for other colors if the ones you've given aren't conformant. Note, though, that it's not making an aesthetic assessment.