BuddyPress.org

Its controlled by NAV element.

Just had a quick look in default.css

div.item-list-tabs {
clear: left;
overflow: hidden;
margin: 25px -19px 20px -19px;
background: #eaeaea;
}
div.item-list-tabs ul li a {
text-decoration: none;
}

div.item-list-tabs ul {
width: 100%;
}
div.item-list-tabs ul li {
float: left;
margin: 5px 0 0 5px;
}
div.item-list-tabs#subnav ul li {
margin-top: 0;
}

div.item-list-tabs ul li:first-child {
margin-left: 20px;
}

div.item-list-tabs ul li.last {
float: right;
margin: 7px 20px 0 0;
}
div.item-list-tabs#subnav ul li.last {
margin-top: 4px;
}

div.item-list-tabs ul li.last select {
max-width: 175px;
}

div.item-list-tabs ul li a,
div.item-list-tabs ul li span {
display: block;
padding: 5px 10px;
text-decoration: none;
}
div.item-list-tabs ul li span {
color: #aaa;
}

div.item-list-tabs ul li a span {
display: inline;
padding: 0;
color: inherit;
}

div.item-list-tabs ul li.selected a,
div.item-list-tabs ul li.current a {
background-color: #fff;
color: #555;
font-weight: bold;
-moz-border-radius-topleft: 3px;
-webkit-border-top-left-radius: 3px;
-moz-border-radius-topright: 3px;
-webkit-border-top-right-radius: 3px;
}
ul li.loading a {
background-image: url( ../images/ajax-loader.gif );
background-position: 92% 50%;
background-repeat: no-repeat;
padding-right: 30px !important;
}
div#item-nav ul li.loading a {
background-position: 88% 50%;
}

div.item-list-tabs#object-nav {
margin-top: 0;
}

div.item-list-tabs#subnav {
background: #fff;
margin: -15px -19px 15px -19px;
border-bottom: 1px solid #eaeaea;
min-height: 35px;
overflow: hidden;
}

div.item-list-tabs ul li.feed a {
background: url( ../images/rss.png ) center left no-repeat;
padding-left: 20px;
}

Change the #colours to suit.

I think that is correct. Apologies if not