How to make Word documents accessible

Colour contrast

Good colour contrast helps more people see, read and understand content, including those using assistive technologies.

On this page

Using colour in documents

Text and images in your document must be clear and easy to read.

Good contrast makes text clearer, reduces eye strain and helps people find information quickly, especially on screens or in different lighting.

It is especially important for people with low vision, people using screen magnifiers, and people with visual or cognitive differences.

This includes:

  • normal and large text
  • content in images (such as charts and diagrams)
  • interactive elements, such as form fields or buttons

Decorative images and logos do not need to meet contrast requirements.

Use clear contrast

Use strong contrast, such as:

  • dark text on a light background
  • light text on a dark background

Avoid:

  • bright colours on dark backgrounds
  • text placed on busy images

These combinations can be difficult to read and may cause eye strain.

Do not rely on colour alone

Do not rely on colour alone to show meaning, as some people cannot distinguish between certain colours.

Always include:

  • text labels
  • patterns
  • other visual cues

This is especially important for charts and graphs.

Colour contrast and text sizes

Colour contrast is the difference between text and its background. Higher contrast improves readability.

You do not need to calculate contrast yourself, but it helps to understand minimum standards.

Minimum contrast ratios:

  • 4.5:1 for normal text 
  • 3:1 for large text 

In Word:

  • normal text is usually under 18 point, or under 14 point if bold  
  • large text is 18 point or larger, or 14 point or larger if bold  

For best results, aim for:

  • around 7:1 for normal text
  • around 4.5:1 for large text

These higher ratios improve accessibility for more users.

Choosing text colours

When setting text colour, for example in headings:

  • avoid very low or very high contrast colour combinations
  • do not use colour alone to show meaning, for example, red text to show importance
  • check that text over backgrounds such as photos or patterned images is still readable

Many of Word’s built-in styles do not meet accessibility requirements, so check them before use.

To modify or change a heading style colour in Word:

  • Select Styles, then select the text style (for example, Heading 1).
  • Right-click and select Modify.
  • Use the formatting toolbar to change the colour.

Using images and visual elements

Non-text content must meet a minimum contrast ratio of at least 3:1.

This includes:

  • informative images such as charts, diagrams, and graphs
  • images of text
  • shapes or visual elements that have meaning
  • interactive components, like form fields

For example, a line chart must have clear contrast between:

  • the lines and the background
  • lines shown next to each other

Decorative images do not need to meet contrast requirements.

How to check colour contrast

Microsoft's Accessibility Checker

Word’s Accessibility Checker can help find contrast issues in text. However, it does not check contrast in images, text boxes or shapes

Learn more about Microsoft's Accessibility Checker

WebAIM Contrast Checker

WebAIM’s Contrast Checker is a free web-based tool.

  • use the colour picker or enter colour values (hex or RGB)
  • check colours meet WCAG AA contrast ratios

Check colours using WebAIM's Contrast Checker

Other colour tools and resources

You can use a colour's hex code (like #FFFFFF) with the following online tools:

Accessibility standards and resources

Following this guidance makes content easier to read and access for more people and supports meeting UK accessibility regulations, including PSBAR 2018.

For more on colour contrast:

If system or format limits stop you from following this guidance, contact the Communications and Marketing team before publishing.