silverstripe-tagfield/css/TagField.css

.field.tag span.tagMatches {
   display: block;
	margin-top: 5px;
}

.field.tag  span.tagMatches span {
    padding: 2px;
    margin-right: 4px;
    background-color: #4EA3D7;
    color: #fff;
    cursor: pointer;
}