OpenLayers 3 Beginner’s Guide

The icon style

<!doctype html>
<html>
  <head>
    <title>Vector Style Examples</title>
    <link rel="stylesheet" href="../assets/ol3/css/ol.css" type="text/css" />
    <link rel="stylesheet" href="../assets/css/samples.css" type="text/css" />
  </head>
  <body>
    <div id="map" class="map"></div>
    <script src="../assets/ol3/js/ol.js"></script>
    <script>
      // the icon style allows picking a section out of a larger image
      var earthquakeStyle = new ol.style.Style({
        image: new ol.style.Icon({
          anchor: [0.5, 0.5],
          size: [52, 52],
          offset: [52, 0],
          opacity: 1,
          scale: 0.25,
          src: '../assets/img/dots.png'
        })
      });
      var countryStyle = new ol.style.Style({
        fill: new ol.style.Fill({
          color: [0, 255, 255, 1]
        }),
        stroke: new ol.style.Stroke({
          color: [127,127,127,1.0],
          width: 1,
          lineJoin: 'round'
        })
      });
      var timezoneStyle = new ol.style.Style({
        stroke: new ol.style.Stroke({
          color: [127,127,127,1.0],
          width: 1,
          lineJoin: 'round',
          lineCap: 'round'
        })
      });
      var countries = new ol.layer.Vector({
        source: new ol.source.GeoJSON({
          projection: 'EPSG:3857',
          url: '../assets/data/countries.geojson'
        }),
        style: countryStyle
      });
      var timezones = new ol.layer.Vector({
        source: new ol.source.KML({
          projection: 'EPSG:3857',
          url: '../assets/data/timezones.kml',
          extractStyles: false
        }),
        style: timezoneStyle
      });

      var earthquakes = new ol.layer.Vector({
        source: new ol.source.KML({
          projection: 'EPSG:3857',
          url: '../assets/data/earthquakes.kml',
          extractStyles: false
        }),
        style: earthquakeStyle
      });

      var center = ol.proj.transform([0, 0], 'EPSG:4326', 'EPSG:3857');
      var view = new ol.View({
        center: center,
        zoom: 1
      });
      var map = new ol.Map({
        target: 'map',
        layers: [countries, timezones, earthquakes],
        view: view
      });

      earthquakes.once('render', function() {
        view.fitExtent(earthquakes.getSource().getExtent(), map.getSize());
      });
    </script>
  </body>
</html>