You can change the default hyperlink style for an entire publication by overriding the link style in HeadCSS:
.default_link{
border-bottom: solid 1px #00ccff;
margin-bottom:5px;
}
.default_link:hover {
filter: alpha(opacity=20); -moz-opacity:0.2;-khtml-opacity:0.2;opacity:0.2;
background-color: #00ccff;
}