JSFiddle - React, Tailwind, and code Playground

HTML

<div class="primary-billing">
<div>1</div>
<div>4</div>
<div>3</div>
<div>10</div>
<div>5</div>
<div>5</div>
 <div>4</div>
<div>3</div>
<div>10</div>
<div>5</div>
<div>5</div>
<div>1</div>
<div>4</div>
<div>3</div>
<div>10</div>
<div>5</div>
<div>5</div>
 <div>4</div>
<div>3</div>
<div>10</div>
<div>5</div>
<div>5</div>
<div>1</div>
<div>4</div>
<div>3</div>
<div>10</div>
<div>5</div>
<div>5</div>
 <div>4</div>
<div>3</div>
<div>10</div>
<div>5</div>
<div>5</div>
<div>1</div>
<div>4</div>
<div>3</div>
<div>10</div>
<div>5</div>
<div>5</div>
 <div>4</div>
<div>3</div>
<div>10</div>
<div>5</div>
<div>5</div>
</div>

JavaScript

var colors = ['red', 'orange', 'yellow', 'green', 'pink', 'brown'];
$('.primary-billing').children().each(function(i){
  $(this).css('background', colors[Math.floor(i/2)%colors.length]);
});