[Seven Skins]

I would do it something like this ...
Add this to additional.css

.postbitlegacy .postrow a,
.eventbit .eventrow a,
.postbitdeleted .postrow a,
.postbitignored .postrow a {
	text-decoration: underline;
}

.postbitlegacy .postrow a:hover,
.eventbit .eventrow a:hover,
.postbitdeleted .postrow a:hover,
.postbitignored .postrow a:hover {
	color: red;
}

Change the color red to your requirements.