Thank you so much, it works!
For the sake of completeness, here's the relevant parts of the updated user stylesheet:
Code:
a:link, a:visited {
color: #5d718c !important;
}
a:hover {
color: #7a97ba !important;
}
a:active {
color: #1151a0 !important;
}
And this is what it looks like now: