JSFiddle - React, Tailwind, and code Playground
HTML
<ul>
<li class="display_class">test 1</li>
<li class="display_class">test 2 should be in green</li>
<li class="display_class">test 3 should be in green</li>
<li class="display_class">test 4</li>
</ul>
CSS
.display_class:nth-child(-n+1){
background-color:green;
}