Swapping font-color on click

If I have a navigation menu that is styled with CSS and I want the font-color of one of the navigation elements to change on click, how can I do this? For example, if they are all styled to have a font-color of #333333 and when you roll over it, the font color changes to #b20000, but when you click on the link, I want the font-color to stay at #b20000 to show it as active, but then return to #333333 when you go to the next active page. Thanks!