Edit in JSFiddle

$('a').popover()

<a href="#" class="btn" rel="popover" data-placement="bottom" data-content="Vivamus sagittis lacus vel augue laoreet rutrum faucibus." data-color="yellow" title="Popover on right">Yellow popover</a>
<a href="#" class="btn" rel="popover" data-placement="bottom" data-content="Vivamus sagittis lacus vel augue laoreet rutrum faucibus." data-color="blue" title="Popover on bottom">Blue popover</a>

body {
    padding: 40px;
}

[rel=popover][data-color=yellow] + .popover {
    background: yellow;
}

[rel=popover][data-color=blue] + .popover {
    background: blue;
}