Colour and colour contrast: accessibility for designers

  • Author: Access iQ ®
  • Date: 3 Mar 2015
  • Access: Premium

Quick facts

Colour and colour contrast are some of the easier accessibility requirements to comply with, as elements have numeric targets that are easier to measure against.

  • Sufficient colour contrast between text and its background assists people with moderately low vision to read your text.
  • The contrast between the colour of text and its background must meet colour contrast requirements defined in WCAG 2.0.
  • Colour must not be used alone to convey information to the user. Use another method in addition to colour, such as text styling (emphasis or strong emphasis) or a text label.
  • Colour and contrast requirements apply to the normal state of a link as well as visited, hover and focus states.

People can be affected by various forms and degrees of vision impairment, including:

  • Low vision
  • Macular degeneration
  • Visual acuity
  • Spatial blindness
  • Colour blindness

Colour blindness can affect as much as 10-12 per cent of the population, therefore ensuring that a website accommodates people with vision impairments clearly benefits a significant proportion of any audience.

Colour and colour contrast are some of the easier accessibility requirements to comply with, as elements have numeric targets that are easier to measure against. In order to check colour and contrast effectively and accurately, designers need to be aware of all the conditions to check against, which are outlined within this topic.

Note: When searching online for information on issues with colour, make sure to include the US spelling of "color" as the two spellings can return different results.

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