Each style is a different CSS class from the jquery.qtip.css
file.
.qtip-shadow
adds the shadow.qtip-rounded
adds the rounded edges.qtip-yellow
adds the yellow color (etc.. etc..)
When you view the uncompressed CSS file. All the class names after .qtip-default
that are in the first column are style modifiers.
To create a yellow qtip
$(".tooltip").qtip({style:{classes: "qtip-yellow"});
To apply styles from qtip element
<div class="tooltip" data-style="qtip-yellow"/>
$(".tooltip").each(function(){
$(this).qtip({style:{classes: $(this).data("style")});
});