This section of the site is no longer being formally maintained, although new items may be added periodically.
Visual Impairments
Can Colour-Blind Users See Your Site?
This article by Microsoft discusses the causes of the various forms of colour blindness and proposes some solutions.
http://msdn.microsoft.com/library/en-us/dnhess/html/hess10092000.asp
Colour Vision, Colour Deficiency
An article by Diane Wilson of Firelily Design.
www.firelily.com/opinions/color.html
Effective Color Contrast
This article by Lighthouse International provides guidance when designing for people with partial sight and colour deficiencies.
www.lighthouse.org/color_contrast.htm
Ishihara Test for Colour Blindness
www.toledo-bend.com/colorblind/Ishihara.html
Resource Guide for People with Visual Impairments
This section of the Microsoft website provides a wide range of resources for developers and end-users.
www.microsoft.com/enable/guides/vision.htm
Royal National Institute for the Blind (RNIB)
The RNIB campaigns for good website design via its See it Right Campaign, and has produced both online and printed guidelines.
www.rnib.org.uk/digital/siraccess/webconsult.htm
Safe Web Colours for Colour-Deficient Vision
A comprehensive discussion of the topic by Christine Rigden of BTexact Technologies.