Color Accessibility Workflows
The Web Content #Accessibility Guidelines (WCAG) 2.0 contain recommendations from the World Wide Web Consortium (W3C) for making the web more accessible to users with disabilities, including #color blindness and other vision deficiencies.
One of my favorite tools is Lea Verou’s Contrast Ratio. It gives you the option of entering a color code for a background and a color code for text, and it calculates the ratio for you.
Another great tool that has the benefit of simultaneously showing whether a color combination passes both AA and AAA compliance levels is Jonathan Snook’s Colour Contrast Check