Can someone please explain how to override the style of the
pseudo-class in particular tag or block?

Specifically, I need to override the link, active, and visited
pseudo-classes for a set of anchors in an unnumbered list.

For my last try, I defined the following ID selector:

#xxx a, #xxx a:link, #xxx a:active, #xxx a.visited {
color: white;
}

And in the HTML:

<a id="xxx" href="..." title="yyy">zzz</a>

The anchor is still displayed with the style defined globally by a
style like this:

a:link {
color: #ff3333;
}