You can finally walk in colour-blind person’s shoes with this tool.
Color Oracle is a free color blindness simulator for Window, Mac and Linux. It takes the guesswork out of designing for color blindness by showing you in real time what people with common color vision impairments will see.
Source: Color Oracle
Source: HTML Color Codes
Color Safe is a tool to explore beautiful, accessible color palettes for your website based on Web Content Accessibility Guidelines (WCAG).
This site tests which new HTML5 features are accessibly supported by major browsers. This includes if they are keyboard accessible, mapped to the platform accessibility APIs, and if any accessibility related features are supported. An accessibly supported feature means it is usable by people who rely on assistive technology, without developers having to supplement with ARIA or other additional workarounds.
Source: HTML5 accessibility