We've had this problem since Cata release when we switched to one of the Cata templates. Links from Wowhead for Common-quality items (white) show up as black when posted anywhere on our site (forums, news, guides, etc).

Currently we're using a custom CSS file and I was wondering if there's a place in it to modify this. If not, I'm not really sure what else is causing it, but it's pretty hard to read black text against a dark-gray background.

Our site is aotp.dkpsystem.com

The color is set from itemlinks.css defined on line 12 here (#1C1C1C)

.quality,.quality-1,.quality0,.quality1,.quality2,.quality3,.quality4,.quality5,.quality6,
.quality:link,.quality-1:link,.quality0:link,.quality1:link,.quality2:link,.quality3:link,.quality4:link,.quality5:link,.quality6:link {
	padding-right: 5px;
	letter-spacing: 1px;
	font-weight: bold;
}


a.quality-1, a.quality-1:link, a.quality-1:visited { color: #FFCC00; }
a.quality0, a.quality0:link, a.quality0:visited  { color: #808080; }
a.quality, a.quality:link, a.quality:visited,
a.quality1, a.quality1:link, a.quality1:visited  { color: #1C1C1C; }
a.quality2, a.quality2:link, a.quality2:visited  { color: #00FF00; }
a.quality3, a.quality3:link, a.quality3:visited  { color: #0068FF; }
a.quality4, a.quality4:link, a.quality4:visited  { color: #8020FF}
a.quality5, a.quality5:link, a.quality5:visited  { color: #FF8000; }
a.quality6, a.quality6:link, a.quality6:visited  { color: #FF2020; }


table.ttb {
	background-color: #282828;
	color: #FFFFFF;
	margin: 1px;
	font-size: 11px;
	border: 1px solid #FFFFFF;
	padding: 3px;
}

If I define a.quality in my own CSS will it overwrite itemlinks.css?

Fixed in the template. Thanks for the heads up.