JSFiddle - React, Tailwind, and code Playground

HTML

<a id="listitem0" href="http://google.com.au/">http://google.com.au/</a>

<br />
<a id="listitem1" href="http://stackoverflow.com/">http://stackoverflow.com/</a>

<br />
<a id="listitem2" href="http://kbbdigital.com.au/">http://kbbdigital.com.au/</a>

<br />
<a id="listitem3" href="http://netreach.com.au/">http://netreach.com.au/</a>

<br />

CSS

a {
    color:#999999;
    background-color:#000;
}
a:visited {
    color:#00FF00;
    background-color:#30F;
}

JavaScript

var element = document.getElementById("listitem0");
style = window.getComputedStyle(element),
color = style.getPropertyValue('color'),
background = style.getPropertyValue('background-Color');

console.log(color, background);