Because the _colors hash is filled with CamelCased names and _parseHex() lowercases its input before looking it up in _colors, it never recognizes w3c-defined names. Consequently, w3c-defined names passed in via options.color and the setColor() method aren't recognized either.
In toolness/lovebomb.me@aff9a94 I've patched the code by creating a separate hash called _lowerColors and looking up lowercased input in that. Let me know if you think this is a decent solution and I'll make a unit test for it and submit it as a pull request.
Thanks for the notice.
I've just made all color names lowercase instead, seeing as they are used only for reading.
Cool, thanks Martijn!