JSFiddle - React, Tailwind, and code Playground
by gRoberts
HTML
<ul>
<li>-</li>
<li>-</li>
<li>-</li>
<li>-</li>
<li>-</li>
<li>-</li>
<li>-</li>
<li>-</li>
<li>-</li>
<li>-</li>
<li>-</li>
<li>-</li>
<li>-</li>
<li>-</li>
<li>-</li>
</ul>
CSS
li:nth-child(5n+4),
li:nth-child(5n+10),
li:nth-child(10n+5){
background: red;
}