You can change like that black theme in headder you can edit the header.tpl in templates folder.you can see hd section in headder.tpl see folowwing code
Code:
<div id="hd">----headder content is here---</div>
this diviation is used for vshare headder section.you can edit this whole section to make complete changes if you want .youcan see this style in style.css.

You can see the vshare menu in headder.tpl.look below
Code:
<table class="menu">
<tr align="center">
<td width="14%">HOME</td>
<td width="15%">UPLOAD</td>
<td width="15%">WATCH</td>
<td width="14%">TAGS</td>
<td width="14%">PICTURES</td>
<td width="14%">CHANNELS</td>
<td width="14%">GROUPS</td>
<td width="14%">FRIENDS</td>
<td width="14%" style="border:0px">MEMBERS</td>
</tr>
</table>
Edit style.css in template folder.look at the following code. its vshare headder menu css.you can replace as your own black style

Code:
a.menu, a.menu:link, a.menu:link:visited {
font-family: Verdana, Arial;
font-size: 14px;
color: #FFFFFF;
font-weight: bold;
}

a.menu:hover { color: #FF0; }

a.submenu, a.submenu:link, a.submenu:link:visited, .submenu {
font-family: verdana, arial;
font-size: 11px;
color: #2b376b;
}
Then you can replace the menu.gif its under templates->images->menu.gif
you can see this "menu.gif" is used for vshare headder menu image.You can replace this for your own image