Hi
You can try adding this to your custom.css file
.t3-topnav .nav > li > a:hover, .t3-topnav .nav > li > a:focus {
background-color:#yournewcolor!important;
color:#yournewcolor!important;
}
You can find all topnav settings in this file /templates/ja_teline_v/css/template.css
.t3-topnav .nav > li {
display: block;
float: left;
margin: 0;
}
.t3-topnav .nav > li > a {
color: #333333;
text-transform: uppercase;
font-weight: 700;
font-size: 12px;
font-family: "Roboto Condensed", "Arial Narrow", "Helvetica Neue", Helvetica, Arial, sans-serif;
padding: 0 40px;
height: 48px;
line-height: 48px;
border-radius: 0;
border-right: 1px solid #e5e5e5;
}
.t3-topnav .nav > li > a:hover,
.t3-topnav .nav > li > a:focus {
color: #fff;
background-color: #111111;
border-color: #111111;
}
.t3-topnav .nav > .active > a,
.t3-topnav .nav > .active > a:hover,
.t3-topnav .nav > .active > a:focus {
color: #333333;
background-color: #fff;
border-color: #e5e5e5;
}
Hope it helps