<http://schema.org/description>
"We notice that the black extrusions have a greenish cast to them when we receive them from the anodizer. When the parts are exposed to plant lighting and to indirect sunlight, they turn a purplish color after six months or less."^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.pfonline.com/articles/anodized-and-dyed-black-extrusions-turning-green-and-purple>