title: Highmaps min/max color not working as expected
body: <p>I am trying to visualise data values on a world map using Highcharts.</p>
  
  <p>The highest value should be displayed as black fill on the map and minimal value as a white area. However the plotted colors are not matching the minColor and maxColor setup.</p>
  
  <p>Am I doing something wrong or is it a bug in Highmaps?</p>
  
  <p>Here is the full sample code. I also prepared a JSFiddle mock. Thank you for your help.</p>
  
  <pre><code>// sample data
  var values = [
    {
      code: "PL",
      value: 743
    },
    {
      code: "FR",
      value: 8205
    },
    {
      code: "DE",
      value: 2303
    },
    {
      code: "BR",
      value: 9404
    },
    {
      code: "ZA",
      value: 2937
    },
    {
      code: "ES",
      value: 2390
    },
    {
      code: "IE",
      value: 2604
    },
    {
      code: "UK",
      value: 5302
    },
    {
      code: "US",
      value: 5178
    }
  ];
  
  // init min/max with first item
  var valuesMin = values[0].value;
  var valuesMax = values[0].value;
  
  // find the real min and max
  for(var i=0; i&lt;=values.length-1; i++) {
    // save max of all interactions
    if (values[i].value &gt; valuesMax) {
      valuesMax = values[i].value;
    }
    // save min of all interactions
    if (values[i].value &lt; valuesMin) {
      valuesMin = values[i].value;
    }
  }
  
  // doublecheck min and max boundaries
  console.log(valuesMin);
  console.log(valuesMax);
  
  // Initiate the chart
  var config = {
    chart: {
      renderTo: 'container',
      type: 'map',
      spacing: [0,0,0,0],
      plotBorderWidth: 0,
      plotBackgroundColor: '#ffffff'
    },
  
    title: {
      text: ''
    },
    subtitle: {
      text: ''
    },
    legend: {
      enabled: false
    },
    credits: {
      enabled: false
    },
    tooltip: {
      enabled: false
    },
    mapNavigation: {
      enabled: false
    },
  
    colorAxis: {
      minColor: '#ffffff',
      maxColor: '#000000',
      min: valuesMin,
      max: valuesMax,
      minorTickInterval: 0.1,
      tickLength: 0,
      type: 'linear'
    },
  
    plotOptions: {
      map: {
        states: {
          hover: {
            enabled: false
          },
          normal: {
            animation: false
          }
        }
      }
    },
  
    // The map series
    series : [
      {
        mapData: Highcharts.maps['custom/world'],
        data : values,
        joinBy: ['iso-a2', 'code']
      }
  
    ]
  };
  
  console.log(values);
  
  var chart = new Highcharts.Map(config);
  </code></pre>
  
  <p>Fiddle <a href="http://jsfiddle.net/tomexx/bpg544f4/" rel="nofollow">http://jsfiddle.net/tomexx/bpg544f4/</a></p>