It used to be an important/useful feature of the web/html -- until "website designers" decided that they didn't like the look and started making certain that all links looked the same, and other things that also made it stop working.
I have a question - why the ****** does a website need to have/see/retreive the list of URLs I've been at in order to do this - coloring links is a browser side feature! The only thing a website needs to do is suggest which colors to use for said links.
This was grossly unintentional right? Someone didn't choose to implement this specific behaviour, right?