JGrowl set theme

The .test background-color is overridden by the "div.jGrowl div.jGrowl-notification" style. You could make the .test style !important:

.test{
    background-color:       #000000 !important;
}

or access the .test class more specifically like so:

"div.jGrowl div.jGrowl-notification.ui-state-test"

this will override it too