JSFiddle - React, Tailwind, and code Playground

HTML

<div id="h1">██</div>

JavaScript

var myFunctions = [Red, Green, Blue]

var i=0, timer = setInterval(()=>{
  if (i < myFunctions.length) myFunctions[i++]()
  else clearInterval(timer)
}, 1000)

function Red() {
  h1.style.color = 'red';
}
function Green() {
  h1.style.color = 'green';
}
function Blue() {
  h1.style.color = 'blue';
}