JSFiddle - React, Tailwind, and code Playground

HTML

<html>
	<head>
		<style>
		body {
		overflow:hidden;
		background:#333;
		}
		canvas {
    border:5px solid black;
}
ul {
    list-style-type:none;
    margin:0;
    padding:0;
    border:0;
    height:30px;
}
li {
    margin:0;
    padding:0;
    border:2px solid white;
    display:block;
    float:left;
    width:30px;
    height:30px;
    cursor:pointer;
}
li.active {
    border:2px solid #666;
}
a, a:hover {
    margin-top:10px;
    font-family:Arial, sans-serif;
    display:block;
    width:220px;
    padding:5px 10px;
    background:#3d6aa2;
    color:white;
    text-decoration:none;
    font-size:2em;
    text-align:center;
}

#drawingPad{
	background:#fff;
}
#palette fieldset {
    display: inline-block;
    width: 25%;
    margin: 0px;
	box-sizing:border-box;
	text-align:center;
}

input#brushsize {
    margin: 30px;
    display: inline-block;
    vertical-align: top;
}

a#clear {
    display: inline-block;
    vertical-align: top;
    font-size: 14px;
    width: 100px;
    margin: 23px;
}
fieldset {
    background: #fff6;
    border: 2px solid #000c;
    margin: 0px;
	padding:14px 0px;
	}

output#hex {
    padding: 10px;
    width: 24%;
    display: inline-block;
    vertical-align: top;
    font-size: 17px;
    box-sizing: border-box;
    text-align: center;
    background: #fff6;
    border: 2px solid #000c;
	height: 44px;
}

ul#palette {
    font-size: 0px;
}

#r,#g,#b {
  -webkit-appearance: none;
  height: 8px;
    border-radius:50px;
  background: #c9c9c9;
  opacity: 1;
}

#r::-webkit-slider-thumb,
#g::-webkit-slider-thumb,
#b::-webkit-slider-thumb{
  -webkit-appearance: none;
  appearance: none;
  width: 15px;
  height: 15px;
  border-radius:50px;
  cursor: pointer;
}
#r::-webkit-slider-thumb{
    background: #E91E63;
}
#g::-webkit-slider-thumb{
    background: #4CAF50;
}
#b::-webkit-slider-thumb{
    background: #03A9F4;
}
		</style>
	</head>
	<body>
	<canvas id="drawingPad" width="200" height="200"></canvas>
<ul id="palette">
    <fieldset>
			...