For chrome, use the stylish extension

There should be a button that has a S there right click that then go to options.

Then in the code box put "a:visited { color: #FF0000; }"

Under that where it says URL I put http://www.marapets.com/online.php I'm not sure if you need this.

Then on left side name it something I put Mara.

Then press Save.

Click names and the color should change.

Note to self/others.

http://imgur.com/a/IQveV