How to Change Background Color in JS 🎨 [+project]

Here is the general solution – a line of Javascript code that changes the background color: = COLOR

// change background color in JS

Here are a few examples of changing background color:

// example #1 = '#ff0000';

// in this example the DOM element is body (document.body)
// color is "#ff0000"
// this will change background color of body element to #ff0000 (red)
// example #2
document.querySelector('.your-css-selector').style.backgroundColor = 'green';

// in this example the DOM element is "your-css-selector" selector
// the color is green

Knowing this you can change background color of any DOM element.

As I frontend developer I decided to do a small project to master changing background color.

Project: Background color change in JS

// change background color in JS

Take a look and play with it clicking the paint image, which is acting like a button for changing background color.

See the Pen JS100::01-Change Background Color by jsSecrets (@jssecrets) on CodePen.

change background color in JS
change background color in JS

Code explanation

// change background color in JS


// change background color in JS


    <div class="change-color-btn">
      <img src="img/paints.png" />

Here I use only one <div> that acts like a button. And inserted an image inside.


// change background color in JS

/* Basic reset */ 
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;

body {
  height: 100vh;
/* set initial background color body */
  background-color: radial-gradient(
    rgb(255, 255, 255) 70%,
    rgb(243, 243, 243) 100%

/* Flexbox properties align button
 horizontally and vertically centered  */ 
  display: flex;
  justify-content: center;
  align-items: center;

/* Transition properties make color
 changing more smooth */ 
  transition: all 750ms;
  transition-delay: 0;

.change-color-btn {
  width: 160px;
  height: 160px;
  background: white;
  border-radius: 100%;
  box-shadow: 0 10px 25px rgba(124, 130, 141, 0.2);
  position: relative;
  cursor: pointer;
  transition: all 0.25s ease-out;
.change-color-btn:hover {
  transform: translateY(-5px);
.change-color-btn img {
  max-width: 70%;

/* Position the image in the very center
 of the parent <div> block */ 
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  user-select: none;


// change background color in JS

//// Variables

/* first off, I create an array and
 fill it with a colors in the HEX format.
It can be any number of colors.
const colors = ['#7b68ee', '#eb3dae', '#f7ce51', '#5bc5fa'];

/* next, create a "colorIndex" variable.
It will act as a box for an intermediate color.
let colorIndex = 0;

/* lastly, select our button for changing color */
const button = document.querySelector('.change-color-btn');

//// Functions

/* our function that will be invoked on a 'click' event */
const changeColor = () => {

  /* our DOM element is body (document.body)  */
  /* our color on the first click is the 'colors[0]' */
  /* 'colors[0]' is the first element of 'colors' array  */ = colors[colorIndex];

  /* next we have a conditional (ternary) operator */
  /* it means if the value of 'colorIndex' variable
     less than length of the array, then increase it.
     otherwise, set it to zero 
  /* Hope you understand why we have 'length - 1' ? */
  colorIndex < colors.length - 1 ? colorIndex++ : (colorIndex = 0);

  /* The last line of code creates a loop
     to change background infinitely  */

//// Event Listeners

/* add event listener on button */
button.addEventListener('click', changeColor);

In this project I change background of body element, but it can done with any HTML element.

Let me also show you how to change background on any element with a custom function.

Custom function

/* our custom function that will change a background */
/* it accepts two parameters */
/* an element and a color */
const bgColorChange = (element, color) => { = color;

/* function call */
/* our element is the '.box' selector element */
/* the color is yellow */
bgColorChange(document.querySelector('.box'), 'yellow');

Try this code and you will see the result 🙂.

I also want to share couple of ideas on projects where you can practice changing backgorund color with JS.

Project ideas

1️⃣ Change background with a random color

You can accomplish this in different ways. For instance, every time you click a button a random color is generated or generate an array of random colors.

2️⃣ Pick a background color

Even more ideas here, pick a color from a dropdown list or just create a color grid. More advanced javascripters may use a color wheel component.

Do you have any other idea?


Share it in comments 🙂

What to do next?

You can explore some of my latest projects here.

If you have some Javascript project in mind that you want me to explain, please write it in the comments.


1️⃣ Work illustrations by Storyset

Ilyas Seisov

Ilyas Seisov

UI/Web designer and Javascript developer with Master's degree in Computer Science. He helps businesses transform ideas into reality with the power of design and code. Ilyas creates modern, aesthetic web applications and reads minds in a free time.


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