JSFiddle - React, Tailwind, and code Playground

HTML

<div id="wrapper">
    <div class="button" id="A"></div>
    <div class="button" id="B"></div>
    <div class="button" id="C"></div>
</div>

CSS

.button {
    width: 50px;
    height: 20px;
    float: left;
    border: solid 2px;
    margin: 20px;
}

JavaScript

var buttonArray = ["red","blue","green"];

jackpot(randomizer(), randomizer(), randomizer());

function jackpot(btn1, btn2, btn3) {
    document.getElementById("A").style.backgroundColor = buttonArray[btn1];
    document.getElementById("B").style.backgroundColor = buttonArray[btn2];
    document.getElementById("C").style.backgroundColor = buttonArray[btn3];
}

function randomizer() {
    var color = Math.floor(Math.random()*3);
    return color;
}