That's exactly my point. If I define:

  a .test {
    color: red;
  }
  
  a:visited .test {
    color: green;
  }

Then I could for example using jQuery do:

  $('a .test').each(function() {
    if ( $(this).css('color') == 'green' ) {
      console.log( $(this).parent().attr('href') );
    }
  });

Is that incorrect?