Backround for Text in "Headline Rotator"

if you don’t like to make a general changing you might better give this alb element on your page a custom class
http://kriesi.at/documentation/enfold/turn-on-custom-css-field-for-all-alb-elements/

f.e. : rotator-bg

than try to add to quick css :

#top .rotator-bg  .av-rotator-container-inner {
    background: rgba(255, 255, 255, 0.5) ;
    border-radius: 100px;
    display: inline-block;
    padding: 30px;
    position: relative;
    text-align: center;
    text-shadow: 1px 1px 0 #fff;
    box-shadow: 2px 2px 4px #333 inset;
}

there is a bit more styling in it to show you whats possible

see here in the green field: http://webers-testseite.de/ikom/neue-seite/

Centering the container :

.rotator-bg {
    text-align: center !important;
}