6.5 Colour


Proper contrast between text and background is essential for users who have low vision Therefore the visual presentation of text and images of text MUST have a contrast ratio of at least 4.5:1 except if the text is purely for decorative purpose, is not visible, is a part of an inactive user interface or is a part of a logo where it has no minimum contrast requirement. If the text is substantially large in size (18 pt or 14 pt bold) it must have a contrast ratio of 3:1. (Ref. WCAG 1.4.3)


Use of colour should depend on the target audience. For example, a site for children may use bigger fonts and bright colours to grab the attention of kids while a site designed for researchers and academicians should focus on content with subtle use of colours.


Websites should ensure the colours used for text and graphics look good on a variety of platforms, monitors and devices.


Color is an important asset in presentation of Web content however, some users have difficulty perceiving color e.g. People with partial sight or older users who do not see color well. In addition there are people using text-only, limited-color or monochrome displays and browsers.If a page has information that is conveyed by color differences like: “required fields are red”, “error is shown in red”, and “january sales are in red, july are in blue” or indications of an action like using color to indicate that a link will open in a new window then these users may not be able to access such information. Therefore it MUST be ensured that Color is not used as the only visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element. (Ref. WCAG 1.4.1)