Background of slider

I attempted to change the background color of the slider behind the images by changing it on the style sheet under the section marked

#slider {
position:relative;
height:410px;
padding:30px 0 30px 0;
margin-bottom:20px;
background:#7F9CCB;
-moz-box-shadow:0px 0px 20px #999;
-webkit-box-shadow:0px 0px 20px #999;
box-shadow:0 0 20px #999;

But the color didnt change..any ideas? my website is http://www.gf4u.org/w2