There is almost unlimited potential for the use of colour on web pages. The colour of text, backgrounds and links can be pre-defined by the developer although users of older browsers may not be aware of these and receive simple black on grey or have set up user selected preferences in the browser. Tips on pre-setting the browser are available on the Canadian Institute for the Blind site Developers should be wary of using black backgrounds. The only text colours that are visible against black seem to be white or yellow. When printed these pages use a great deal of ink and are extremely difficult to read.
Coloured backgrounds are very distinctive but the colour of text then needs to be carefully chosen.
Wallpaper backgrounds where there is a pattern appear different on different browsers. There are some sites currently displaying patterned backgrounds which obscure the text. When selecting colours the developer cannot provide combinations suitable for every user but they can help considerably by ensuring that there is high contrast between colour of text and colour of background. This helps users who only have monochrome screens and users with poor visual acuity. Anyone accessing via a telephone and modem who is paying for downloading files may switch off graphics to reduce cost.