Web Accessibility Training
Toronto, Montreal, Ottawa and worldwide via Webex More

WCAG reaches consensus on threshold colours
Some automated contrast checkers rounded contrast rations up

This is color #777777, does it fail WCAG 1.4.3?

Results

  • Wave now fails it at 4.48:1
  • Colour Contrast Tool passes it at 4.5:1
  • Code Sniffer passes it at 4.5:1
  • Juicy Studio pass it at 4.5:1
  • Tenon Passes it least 4.5:1
  • Axe fails it at 4.48:1
  • Snook fails it at 4.48:1
  • Chrome accessbility tools just added code to pass it rounding to 4.5:1

It turns out the actual value appears to be 4.48:1, and Juicy studio, chrome a11y tool, code sniffer, Tenon, and the Colour Contrast tool have rounding to the nearest 10th which pushes it to 4.5:1 to a passes. WCAG says it must be "at least 4.5:1". Webaim tweeted.

I also filed a bug with WCAG to clarify in the understanding document that rounding up to 4.5:1 is either OK or not.

Code

<p style="color:#777777">This is color #777777</p>

Working group reaches consensus

Working Group consensus reached Oct. 27, 2016, regarding the original intent of the Success Criteria. No rounding allowed. It's a threshold value. In other words you cant have any contrast less than that no matter what you did with rounding.

 

Feel free to comment on Twitter @davidmacd

Author information:

David MacDonald is a veteran WCAG member, co-editor of Using WAI ARIA in HTML5 and HTML5 Accessibility Task Force Member. Opinions are my own.




CONTACT US

For a quote or just to chat about your organization's needs


EMAIL

help at can hyphen adapt dot com, (spoken phonetically to trick spam bots)

PHONE

six one three, eight zero six, nine zero zero five

SOCIAL MEDIA