JSFiddle - React, Tailwind, and code Playground

HTML

<div id="main">
        
    </div>

CSS

div {
    /*display: inline-block;*/
    width: 100%;
    float: left;
}
body {
    margin: 0;
}

JavaScript

var params = {
    lines: [
        {
            background: '#0fF',
            updateTime: 1000,
            elements: [
            {
                background: '#00F',
                width: 25
            },
            {
                background: '#f0F',
                width: 50
            },
            {
                background: '#00F',
                width: 25
            }
          ]
        },
        {
            background: '#00F',
            updateTime: 1000,
            elements: [
            {
                background: '#0fF',
                width: 25
            },
            {
                background: '#ff0',
                width: 25
            },
            {
                background: '#0fF',
                width: 25
            },
            {
                background: '#f0F',
                width: 25
            }
          ]
        },
        {
            background: '#0fF',
            updateTime: 1000,
            elements: [
            {
                background: '#00F',
                width: 25
            },
            {
                background: '#f0F',
                width: 50
            },
            {
                background: '#00F',
                width: 25
            }
          ]
        }

    ]
}
function getRandomColor() {
    var letters = '0123456789ABCDEF'.split('');
    var color = '#';
    for (var i = 0; i < 6; i++ ) {
        color += letters[Math.floor(Math.random() * 16)];
    }
    return color;
}

function repaint (lineNum) {
    var line = document.getElementById("main").childNodes[lineNum+1],
        numOfElements = params.lines[lineNum].elements.length;
    for (var i = 0; i<numOfElements; i++){
        line.childNodes[i].style.backgroundColor = getRandomColor();
    }
}
window.onload = function(){
    var line,
        element,        
        height = (window.innerHeight || document.documentElement.clientHeight) / params.lines.length,
        lines =...