Make 2 different classes in css and then swap classes on the links when you click on your link. CSS
a.link{
color : green;
}
a.selected{
color : black;
}
Javascript
jQuery(a).click(function()
{
jQuery('a.selected').addClass('link');
jQuery('a.selected').removeClass('selected');
jQuery(this).removeClass('link');
jQuery(this).addClass('selected');
});