2. Colour

The NZ government agency web site Standards related to using colour on web sites are:

2.1 Information conveyed with colour must be available without colour

Ensure that all information conveyed with colour is also available without colour. This applies principally to navigation labels and error messages.

Guide to this standard

This applies to all content whether done in CMS, templates or completely hand coded sites.

• Use white text with caution.
• Red text, which is often used for important messages, may not be as prominent for a colour-blind person or someone using a black and white monitor. In this case, you should reinforce the message by emphasis <em> or a symbol like “*”.
• Testing should be undertaken on an approved subset of form pages, one of which is a homepage. This will be the basis for testing when a compliance audit is undertaken on an agency site.

Note: ‘Homepage’ is defined in the Glossary of Key Concepts.

Related Standard(s)

2.2 – Contrast between foreground and background colours

This standard covers the W3C WAI checkpoint 2.1 for NZ government agencies.

Rationale for this standard

People who are visually-impaired, including colour blindness, may not perceive differences in colour. Users with browsers that do not support colour or do not support colour well will also be disadvantaged.

2.2 Contrast between foreground and background colours

Ensure that foreground and background colour combinations provide sufficient contrast for navigation, text and informational elements when viewed by someone having colour deficits or when viewed on a black and white screen.

Guide to this standard

• Ensure that background colours contrast with text colours.
• Use white text with caution. Apart from being difficult to read on a light colour background, it may not print if background colours are ignored.
• Avoid patterned backgrounds that make text difficult to read.

This standard covers the W3C WAI checkpoint 2.2 for NZ government agencies.

Related Standard(s)

2.1 – Information conveyed with colour must be available without colour.

Rationale for this standard

• Poor colour contrast is difficult to read, even for users with excellent eyesight. This becomes all the more difficult when users have vision impairments. Bear in mind that there is also a high level of red-green colour blindness in New Zealand.
• There should be good contrast between text colour and the background colour. Patterned backgrounds make text difficult to read, particularly if you have poor vision, and should be avoided.