.header-menu {
position: relative;
z-index: 5;
width: 980px;
margin: 0 auto 30px;
border-top: 1px solid #ddd;
border-bottom: 1px solid #ddd;
padding: 25px 0;
text-align: center;
}
.header-menu {
...
...
background-color:antiquewhite;
}
.header-menu .sublist {
...
...
background-color:aquamarine;
}