Color of slider caption shadow (in rgb or html). Initially it's "#FFF". Note that if shadowSize is 0 then it's an redundant attribute!
In this example, the caption of the left slider has a blue shadow, at the same time, the other one has a red shadow! Look at de difference!
Important: Note that an object embedded is necessary to handle the caption options! And remember: don't forget to fill in the data-caption attribute of the tag img!