Since you stated that you cannot escape IE 6 (sigh), my answer is to completely avoid the problem by introducing a more modern design without highlighting the visited links ... An invisible link always looks the same as a visited link.
Has there been any major, popular, or professional website in the last decade to differentiate "visited" links? Answer: none of those whom I remember.
Why?
People are perceived more intelligently. They already know that they visited the link and do not need a website to tell them.
Websites are better organized. A clear-cut website is less confusing, and people don't need a visual indication of what they have already clicked.
Graphic and visual cues. The websites were mostly plain text, possibly with photographs here and there. You needed a visual indicator to track where you left off reading. Especially since most of the links led you to a completely new page or website. These days, content is visually rich in graphic layouts, icons, smaller text, animation, multimedia, etc. .... you no longer need to depend on the colored text of the “visited” indicator to help you keep track of where you left off.
Difficulty and Ajax. Currently, with rich interactive pages, page refresh is not required to refresh content. However, when you need to refresh the page, people expect the page to return to their original “unreviewed” state. Using the "visit" link, you cannot "reset" a page with a simple refresh, which will lead to confusion; moreover, modern visitors do not expect links to change to a different color.
Confusing and inconsistent. Anyone who has started using the Internet over the past 5-10 years will probably not easily understand why certain links unexpectedly differ from each other on your site and no one.
Not all links are pages or sites. Some links run modal. Some of them make divs open or move. Some control a slide show or other interactive object. The link can call any ajax function you can think of. After you clicked, will these links be considered "visited"? Of course not. To reduce confusion, the concept of a "visited" link is out of date.
- Redundancy
. Most people these days use the same site on different computers, handheld devices, etc. Therefore, the "visited link" is useless anyway. Not to mention the fact that people, as a rule, delete their cache, and also use several browsers on the same computer, again making the highlighted color of the “visited link” unnecessary.
<html> <head> <style type="text/css"> a:link, a:visited { color: black; } </style> </head> <body> <a href="yahoo.com#/test=1">Link1</a>; <a href="yahoo.com#/test=2">Link2</a>; </body> </html>
EDIT . The recommendations made in my answer above were for links, mainly used for site navigation, menus, footers, etc. A valid exception would be links that make up a list of search results.