JSFiddle - React, Tailwind, and code Playground

HTML

<div id="content">
    <div></div>
    <div class="el">Test 1</div>
    <div class="el">Test 1</div>
    <div class="el">Test 1</div>
    <div class="el">Test 1</div>
    <div class="el">Test 1</div>
    <div class="el">Test 1</div>
</div>

CSS

#content {
    background:rgb(200,200,200);
}

.el {
    height:20px;
    background:grey;
    margin-bottom:10px;
}

.el:nth-child(odd) {
    background:green;
}

.el:nth-child(even) {
    background:red;
}