JSFiddle - React, Tailwind, and code Playground

HTML

<div class="buttons">
  <div class="btn btn-reset" data-class="reset"></div>
  <div class="btn btn-red" data-class="red"></div>
  <div class="btn btn-green" data-class="green"></div>
  <div class="btn btn-yellow" data-class="yellow"></div>
</div>

<div class="container custom-class-1 custom-class-2">
  When I click on the colored buttons, then container color class will added/exchanged. When I click on the white button, then it removes container color class. <strong>How to do it?</strong>
</div>

CSS

/* Buttons */
.btn {
  display: inline-block;
  width: 30px;
  height: 30px;
  margin: 3px;
  cursor: pointer;
  border: 2px solid #333;
}
.btn.btn-red { background-color: red; }
.btn.btn-green { background-color: green; }
.btn.btn-yellow { background-color: yellow; }

/* Container */
.container {
  max-width: 480px;
  margin-top: 20px;
  padding: 40px;
  border: 2px solid #DDD;
}

/* Container color classes */
.container.cont-red { background-color: red; }
.container.cont-green { background-color: green; }
.container.cont-yellow { background-color: yellow; }

/* Container custom classes */
.container.custom-class-1 { border-width: 6px; }
.container.custom-class-2 { border-color: #333; }

JavaScript

$('.btn').click(function()
{
    var color = $(this).attr('data-class');

    if ($(this).hasClass('btn-reset')) {
        $('.container').attr('class', 'container')
    } else {
        $('.container').attr('class', 'container cont-'+ color)
    }
})