Colour

Access barriers
Guidelines for overcoming access barriers
Activity

Colour can be used in creative ways to give websites the desired look and feel. It can also be used to convey meaning and assist learners to achieve the intended learning outcomes.

Access barriers

Users who cannot differentiate between particular colours are not able to access information which uses those colours to convey meaning (for example, red/green colour blindness).
Users with devices that have non-colour or non-visual displays are not able to access information which uses colour.
Users with different types of colour deficits, or who have monochrome displays, are not able to see sufficient contrast when foreground and background colours are close in hue.

Guidelines for overcoming access barriers

Make available without colour any important information which is conveyed with use of colour. COLOUR EXAMPLE 1
Provide sufficient contrast between foreground and background colour combinations. COLOUR EXAMPLE 2

Activity

Perform the following W3C suggested tests on your websites to check for colour accessibility by users.

(a) Test to determine if your web document still works without colours

Examine your website with a monochrome monitor or with browser colours turned off. Also try setting up a colour scheme in your browser that uses only black, white and the four browser-safe greys and see how your page holds up.

(b) Test to determine if colour contrast is sufficient for documents to be read by people with colour deficiencies or by those with low resolution monitors

Print pages on a black-and-white printer (with backgrounds and colours appearing in greyscale). Also, try taking the printout and copying it for two or three generations to see the degree to which it degrades. This will show you where you need to add redundant cues (for example, underlining hyperlinks that are presented in colour). It will also show if the cues are too small or indistinct to hold up well.

(c) Use the checklist below to assess any accessibility barriers that may be present in your website as a result of how colour has been used. If you have ticked 'no' for any item go back to the Guidelines for how to overcome this barrier.

Information that is conveyed in colour is also made available in greyscale.

Yes No N/A
Foreground and background colour combinations provide sufficient contrast.

Yes No N/A