<http://schema.org/about>
"Most people likely think they know what color is, but they should try explaining the concept to an 11-year-old. Even scientists have a hard time."^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.mnn.com/green-tech/research-innovations/stories/winners-of-alan-aldas-what-is-color-challenge-announced>