Website color accessibility

Hi,

You can use Blue or Yellow.

Blue is good, but yellow only works if there is a background wash.

You can use the following page to test if colors are correct for WCAG 2.0.

https://webaim.org/resources/contrastchecker/

It will help you to choose colors with enough contrast.

Another great tool is the “WAVE” extension for Chrome browser. It will let you test a complete website for WCAG 2.0. including color contrasts.

Hi michaelaterndrup,

You can calculate the color contrast of a text and it’s background using a tools like:
the WebAIM Color Contrast Checker https://webaim.org/resources/contrastchecker/
The best is if the contrast ratio is 4.5 or higher.

See also the Accessibility handbook: https://make.www.ads-software.com/accessibility/handbook/quick-start-guide/use-of-color/

What you’re looking for is Contrast, not Colour.

Hi michaelaterndrup,

All of these answers are great. There’s also a post that lists other available tools for checking color contrast, as well as to help designers create color palates that meet WCAG 2.0 guidelines: Color contrast tools

Amanda

Yes the accessibility forum is absolutely the right place to ask this question.

Colour blindness is an awkward problem because it comes in different varieties: red/green is just the most common. It affects about 5% of people, and is much more likely to affect men than women.

Having good colour contrast is good advice, but there’s more to it than that.

There’s some basic information here – https://www.colourblindawareness.org/business/

I think as a general rule, don’t use colour as the only indicator and differentiating factor. Use size, font, shape, underlining, emboldening etc too.

There are tools for testing individual images, for example https://www.color-blindness.com/coblis-color-blindness-simulator/ – you could take a screenshot of the website and test that.

There’s the Chrome Daltonize browser add-on but it seemed broken when I tried it: https://chrome.google.com/webstore/detail/chrome-daltonize/efeladnkafmoofnbagdbfaieabmejfcf

There’s also https://michelf.ca/projects/sim-daltonism/ but I don’t have a Mac so can’t test it.

There is some great advice here already, but that won’t stop me from jumping in. Specifically I want to mention that the Web Content Accessibility Guidelines (WCAG) have some points on this that might be worth reading and will inform any errors you get from the tools listed above.

If you end up in a situation where legal compliance is the goal, then WCAG 2.0 is the de facto standard at Level AA (A is the simplest to achive, AAA the most difficult). I say de facto as that is where lawsuit settlements tend to target. I’ve listed a couple items that apply to the issue of color:

1.4.1: Use of Color (Level A)
“Color is not used as the only visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element.”

In short, error messages shouldn’t be just red, links should probably have underlines, don’t tell users to click the blue thing (though this relates as much to 1.3.3), etc.

1.4.3: Contrast (Level AA)
“The visual presentation of text and images of text has a contrast ratio of at least 4.5:1 […] Large-scale text and images of large-scale text have a contrast ratio of at least 3:1.”

Logos and strictly decorative (intentionally illegible) text are exempt. Large text is from ~18px up (there is open debate on px vs pt sizing). The contrast should also apply to text links and the surrounding text. And so on.

Hi michaelaterndrup

I think blue is good