Colbindor is a site devoted to color blindness. It has a number of articles on colorblind facts, as well as tools and a color vision deficiency test.

The best color vision test that I have found on the Web. This test actually gives information as to the type of color blindness and not just a pass fail.

Not an elegant page, but a very useful page for testing how a colorblind person sees your site.

While the colorblindness test is not particularly great, the explanations of colorblindness are very good. The site also includes some great charts between colors as seen by someone without a color vision impairment and someone with an impairment.

Great color charts for the Web designer, and other reference charts

Tools for simulating color blindness.

GreyBit converts a Web page into a grey scale for checking contrast.

Some helpful hints for those with low vision. These tools do work.

The pages on "Effective Color Contrast" and "Making Text Legible" are must reads.

The US Governemnt standard for Web accessibility.

Great color charts for the Web designer, and other reference charts

Accessibility of web content requires semantic information about widgets, structures, and behaviors, in order to allow assistive technologies to convey appropriate information to persons with disabilities. This specification provides an ontology of roles, states, and properties that define accessible user interface elements and can be used to improve the accessibility and interoperability of web content and applications. These semantics are designed to allow an author to properly convey user interface behaviors and structural information in document-level markup, to assistive technologies.

This specification provides guidelines for designing web content authoring tools that are both (1) more accessible for authors with disabilities and (2) designed to enable, support, and promote the production of accessible web content by all authors.

The US Governemnt standard for Web accessibility.

Not the most exciting reading, but the Web Content Accessibility Guidlines set forth the goals that we seek to achieve.

Web Content Accessibility Guidelines (WCAG) 2.0 covers a wide range of recommendations for making Web content more accessible. Following these guidelines will make content accessible to a wider range of people with disabilities, including blindness and low vision, deafness and hearing loss, learning disabilities, cognitive limitations, limited movement, speech disabilities, photosensitivity and combinations of these. Following these guidelines will also often make your Web content more usable to users in general.

This article discusses the Rehabilitation Act as amended for Sections 504 and 508, Americans with Disabilities Act (ADA), Individuals with Disabilities Education Act (IDEA), and Section 255 of the Telecommunications Act of 1996. It provides an excellent overview of these laws, but does not discuss any resulting court cases.