Highcharts Map Demo color

HTML

<script src="https://code.highcharts.com/maps/highmaps.js"></script>
<script src="https://code.highcharts.com/maps/modules/data.js"></script>
<script src="https://code.highcharts.com/mapdata/countries/us/us-all.js"></script>


<div id="container" style="height: 500px; min-width: 310px; max-width: 600px; margin: 0 auto"></div>

JavaScript

$(function () {

	$.getJSON('https://www.highcharts.com/samples/data/jsonp.php?filename=us-population-density.json&callback=?', function (data) {

		// Make codes uppercase to match the map data
		$.each(data, function () {
			this.code = this.code.toUpperCase();
		});

		// Instanciate the map
		$('#container').highcharts('Map', {

			title : {
				text : 'US population density (/km²)'
			},    
	 'legend' : {
		'title' : {
			'text' : 'Percent of live births'
		},
		'layout' : 'vertical'
	},
			colors : ['#D7EDE5', '#7FFF00', '#37A47E'],
			colorAxis : {
				dataClassColor : 'category',
				dataClasses : [{
						to : 57.1,
            name: 'under 57.1'
					}, {
						from : 57.2,
						to : 60.4
					}, {
						from : 60.5,
            name: 'over 60.5'
					}
				]
			},
			series : [{
					states : {
						hover : {
							color : '#BADA55'
						}
					},
					animation : {
						duration : 1000
					},
					data : [{
							'fips' : 'US99',
							'value' : 58.0
						}, {
							'fips' : 'US01',
							'value' : 59.8
						}, {
							'fips' : 'US02',
							'value' : 50.0
						}, {
							'fips' : 'US04',
							'value' : 60.5
						}, {
							'fips' : 'US05',
							'value' : 60.9
						}, {
							'fips' : 'US06',
							'value' : 55.0
						}, {
							'fips' : 'US08',
							'value' : 56.9
						}, {
							'fips' : 'US09',
							'value' : 49.1
						}, {
							'fips' : 'US10',
							'value' : 57.0
						}, {
							'fips' : 'US11',
							'value' : 51.8
						}, {
							'fips' : 'US12',
							'value' : 58.6
						}, {
							'fips' : 'US13',
							'value' : 59.0
						}, {
							'fips' : 'US15',
							'value' : 51.3
						}, {
							'fips' : 'US16',
							'value' : 63.2
						}, {
							'fips' : 'US17',
							'value' : 58.8
						}, {
							'fips' : 'US18',
							'value' : 58.9
						}, {
							'fips' : 'US19',
							'value' : 63.3
						}, {
							'fips' : 'US20',
							'value' : 58.5
						}, {
							'fips' :...