JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
  <li class="a">Hi-1</li>
  <li class="b">Hi-2</li>
  <li class="b">Hi-3</li>
  <li class="a">Hi-4</li>
  <li class="b">Hi-5</li>
  <li class="b">Hi-6</li>
</ul>

CSS

li{
   list-style:none;
 }
.a{
   color:blue;
 }
.b:nth-of-type(3n-1){
  color:red;
}
.b:nth-of-type(3n-3){
  color:violet;
}