JSFiddle - React, Tailwind, and code Playground

HTML

<div id="block1"></div>
<div id="block2"></div>
<div id="block3"></div>
<div id="block4"></div>
<div id="block5"></div>

CSS

div {
  width: 100px;
  height: 50px;
  margin: 5px;
  background: blue;
  cursor: pointer;
}

JavaScript

const elements = Array.from(document.getElementsByTagName('div'))
elements.forEach(block => block.addEventListener('click', (e) => {
	let currentColor = e.target.style.background 
  currentColor ? e.target.style.background = "blue" : e.target.style.background = "red"
}))