Pen Settings

CSS Base

Vendor Prefixing

Add External Stylesheets/Pens

Any URL's added here will be added as <link>s in order, and before the CSS in the editor. If you link to another Pen, it will include the CSS from that Pen. If the preprocessor matches, it will attempt to combine them before processing.

+ add another resource

You're using npm packages, so we've auto-selected Babel for you here, which we require to process imports and make it all work. If you need to use a different JavaScript preprocessor, remove the packages in the npm tab.

Add External Scripts/Pens

Any URL's added here will be added as <script>s in order, and run before the JavaScript in the editor. You can use the URL of any other Pen and it will include the JavaScript from that Pen.

+ add another resource

Use npm Packages

We can make npm packages available for you to use in your JavaScript. We use webpack to prepare them and make them available to import. We'll also process your JavaScript with Babel.

⚠️ This feature can only be used by logged in users.

Code Indentation


Save Automatically?

If active, Pens will autosave every 30 seconds after being saved once.

Auto-Updating Preview

If enabled, the preview panel updates automatically as you code. If disabled, use the "Run" button to update.

HTML Settings

Here you can Sed posuere consectetur est at lobortis. Donec ullamcorper nulla non metus auctor fringilla. Maecenas sed diam eget risus varius blandit sit amet non magna. Donec id elit non mi porta gravida at eget metus. Praesent commodo cursus magna, vel scelerisque nisl consectetur et.

              <h1> The Great 
  <span id ="colorDisplay"> RGB  
  Color Game</h1>
<div id = "stripe">
  <button id ="reset">New Colors</button>
  <span id="message"></span>
  <button class="mode">Easy</button>
  <button class="mode selected">Hard</button>
<div id = "container"> 
  <div class ="square"></div>
  <div class ="square"></div>
  <div class ="square"></div>
  <div class ="square"></div>
  <div class ="square"></div>
  <div class ="square"></div>
              @import url(;

body {
  background-color: #232323;
  margin: 0;
  font-family: 'Ubuntu';

.square {
  width: 30%;
  background: purple; 
  padding-bottom: 30%;
  float: left;
  margin: 1.66%;
  border-radius: 15%;
  transition: background 0.6s;
  -webkit-transition: background 0.6s;
  -moz-transition: background 0.6s;

#container {
  margin: 20px auto;
  max-width: 600px;

h1 {
  color: white;
  line-height: 1.1;
  text-align: center;
  background: steelblue;
  margin: 0;
  font-weight: normal;
  text-transform: uppercase;
  padding: 20px 0;

#colorDisplay {
  font-size: 200%;

#stripe {
  background: white;
  height: 30px;
  text-align: center;

.selected {
  color: white;
  background: steelblue;

button {
  border: none;
  background: none;
  text-transform: uppercase;
  height: 100%;
  font-weight: 700;
  color: steelblue;
  letter-spacing: 1px;
  font-size: inherit; 
  transition: all 0.3s;
  -webkit-transition: all 0.3s;
  -moz-transition: all 0.3s;
  outline: none;

button:hover {
  color: white;
  background: steelblue;

#message {
  display: inline-block;
  width: 20%;
              var numSquares = 6;
var colors = [];
var pickedColor;
var squares = document.querySelectorAll(".square");
var colorDisplay = document.getElementById("colorDisplay");
var messageDisplay = document.querySelector("#message");
var h1 = document.querySelector("h1");
var resetButton = document.querySelector("#reset");
var easyBtn = document.querySelector("#easyBtn");
var hardBtn = document.querySelector("#hardBtn");
var modeButtons = document.querySelectorAll(".mode");


function init() {
  //mode buttons event listeners

function setupModeButtons() {
   for(var i =0; i < modeButtons.length; i++){
    modeButtons[i].addEventListener("click", function(){
    this.textContent === "Easy" ? numSquares = 3: numSquares = 6;

function setupSquares(){
  for(var i = 0; i <squares.length; i++) {
  squares[i].addEventListener("click", function(){
    var clickedColor =;
    if(clickedColor === pickedColor) {
      messageDisplay.textContent = "Correct!";
      resetButton.textContent = "Play Again?";
      changeColors(clickedColor); = clickedColor;
    } else { = "#232323";
      messageDisplay.textContent = "Try Again";

function reset() {
  colors = generateRandomColors(numSquares);
  //pick a new random color from array
  pickedColor = pickColor();
  //change color display to match picked color
  colorDisplay.textContent = pickedColor;
  resetButton.textContent = "New Colors";
  messageDisplay.textContent = "";
  //change color of squares
  for (var i = 0; i < squares.length; i++) {
    if(colors[i]) {
      squares[i].style.display ="block";
      squares[i].style.backgroundColor = colors[i]; 
    } else { 
      squares[i].style.display = "none";    
  } = "steelblue";

resetButton.addEventListener("click", function(){

function changeColors(color) {
  //loop through all squares
  for(var i = 0; i < squares.length; i++) {
   //change each color to given color
    squares[i].style.backgroundColor= color;

function pickColor(){
  var random = Math.floor(Math.random() *      colors.length);
  return colors[random];

function generateRandomColors(num){
  //make an array
  var arr = []
  //repeat num times
  for(var i = 0; i < num; i++){
     //get random color and push into array
  //return that array
  return arr;

function randomColor() {
  // pick a "red" from 0 to 255
  var r = Math.floor(Math.random() * 256);
  // pick a "green" from 0 to 255
  var g = Math.floor(Math.random() * 256);
  // pick a "blue" from 0 to 255
  var b = Math.floor(Math.random() * 256);
  return "rgb(" + r + ", " + g + ", " + b + ")";
🕑 One or more of the npm packages you are using needs to be built. You're the first person to ever need it! We're building it right now and your preview will start updating again when it's ready.