JSFiddle - React, Tailwind, and code Playground

HTML

<button class="changeBg" data-bg="red">Красный</button>
<button class="changeBg" data-bg="blue">Синий</button>
<button class="changeBg" data-bg="yellow">Жёлтый</button>
<button class="changeBg" data-bg="green">Зелёный</button>
<button class="changeBg" data-bg="brown">Коричневый</button>

<div id="background" class="background"></div>

CSS

.background {
  width: 300px;
  height: 300px;
  margin: 100px auto;
  border: 1px solid #aaa;
}

JavaScript

var changeBg = document.querySelectorAll('.changeBg');
var background = document.getElementById('background');

for (var i = 0; i < changeBg.length; i++) {
    changeBg[i].addEventListener('click', function(event){
      event.preventDefault();

      var backgroundColor = this.getAttribute('data-bg');

      background.style.background = backgroundColor;
    }, false);
}