The only CSS property you can apply on :visited links in most webkit-based browsers (like Chrome) is color. This is to prevent history stealing. Also, you can't determine the value of the color CSS property of links from JavaScript. See https://bugs.webkit.org/show_bug.cgi?id=24300 for details.
You can, however, change the style of all links with a{text-decoration: none;}. Here's a demo of the whole affair.
