W3C:

2008-07-21: The Cascading Style Sheets (CSS) Working Group has published the Last Call Working Draft of CSS Color Module Level 3. CSS (Cascading Style Sheets) is a language for describing the rendering of HTML and XML documents on screen, on paper, in speech, etc. It uses color related properties and respective values to color the text, backgrounds, borders, and other parts of elements in a document. This specification describes color values and properties for foreground color and group opacity. These include properties and values from CSS level 2 and new values. Comments are welcome through 01 September. Learn more about the Style Activity. (Permalink)