Use of Colour for Accessibility
Use of Colour is the name of a Level A success criterion in the Web Content Accessibility Guidelines (WCAG). Level A criteria means that any website or app that fails to meet these guidelines – in this case, any website or app that fails to use colour in a way that is accessible for all users – cannot be considered accessible at even the lowest level of conformance.
The rule states that:
Colour is not used as the only visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element.
Not everyone can perceive or see colour in the same way as other people, or are able to easily differentiate one colour from another. The use of colour alone to indicate meaning then becomes a barrier for people with disabilities.
Users who have trouble seeing reds and greens will struggle with a game that asks them to click the green button to start and the red button to stop. Colour-blind individuals will be unable to figure out where they have gone wrong in filling out a form if the only indication they’ve made an error is a red border around a text field.
For this reason, web developers cannot rely solely on colour as a visual cue.
There is a simple process to figure out if a website’s use of colour fails to meet digital accessibility standards. Any web developer can ask themselves these two straightforward questions:
No instructions or information (like charts or graphs) should rely on colour alone.
When in doubt, return to the guiding questions. This is one of many principles that benefits the users who need it most, but also greatly improves websites for every visitor – clear contrast makes your text more readable for all.
As part of our consultations, accessibility audits, and training sessions, we can identify and explain all the contextual nuances that would apply to the WCAG 2.1 Success Criterion 1.4.1 Use of Colour. If you have any questions or need help with any digital accessibility issue, please don’t hesitate to make contact with IA Labs.