JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css">
<div class="container">
    <div class="row">
        <div class="col-xs-3 item">
            <img src="http://placehold.it/80x80?text=[img]">
        </div>
        <div class="col-xs-3 item">
            <img src="http://placehold.it/80x80?text=[img]">
        </div>
        <div class="col-xs-3 item">
            <img src="http://placehold.it/80x80?text=[img]">
        </div>
        <div class="col-xs-3 item">
            <img src="http://placehold.it/80x80?text=[img]">
        </div>
        <div class="col-xs-3 item">
            <img src="http://placehold.it/80x80?text=[img]">
        </div>
        <div class="col-xs-3 item">
            <img src="http://placehold.it/80x80?text=[img]">
        </div>
        <div class="col-xs-3 item">
            <img src="http://placehold.it/80x80?text=[img]">
        </div>
        <div class="col-xs-3 item">
            <img src="http://placehold.it/80x80?text=[img]">
        </div>
        <div class="col-xs-3 item">
            <img src="http://placehold.it/80x80?text=[img]">
        </div>
        <div class="col-xs-3 item">
            <img src="http://placehold.it/80x80?text=[img]">
        </div>
        <div class="col-xs-3 item">
            <img src="http://placehold.it/80x80?text=[img]">
        </div>
        <div class="col-xs-3 item">
            <img src="http://placehold.it/80x80?text=[img]">
        </div>
    </div>
</div>

CSS

img {
    margin-bottom: 1em;
}

.row .item:nth-child(4n+1) {
    background: red;
}