[1] [CITE@en[CSS Color Module Level 3]]
( ([TIME[2010-10-27 00:54:32 +09:00]] 版))
<http://www.w3.org/TR/2010/PR-css3-color-20101028/>

[2] [CITE@en[Tantek-Mozilla-projects - MozillaWiki]]
( ([TIME[2011-01-15 07:24:20 +09:00]] 版))
<https://wiki.mozilla.org/Tantek-Mozilla-projects#CSS4_Color>