<!DOCTYPE html>
<html>
  <head>
    <link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/leaflet/0.7.3/leaflet.css"  data-require="leaflet@0.7.3" data-semver="0.7.3" />
    <link rel="stylesheet" href="style.css" />
  </head>
  <body>
    <div id="map"></div>
    <script type="text/javascript" src="//cdnjs.cloudflare.com/ajax/libs/leaflet/0.7.3/leaflet.js" data-require="leaflet@0.7.3" data-semver="0.7.3"></script>
    <script type="text/javascript" src="script.js"></script>
  </body>
</html>
var map = L.map('map', {
  'center': [0, 0],
  'zoom': 0,
  'layers': [
    L.tileLayer('http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', {
      'attribution': 'Map data &copy; OpenStreetMap contributors'
    })
  ]
});

var rower = {
  "type": "FeatureCollection",
  "features": [{
    "type": "Feature",
    "id": "way/27149688",
    "properties": {
      "type": "way",
      "id": "27149688",
      "tags": {
        "agricultural": "no",
        "bicycle": "yes",
        "highway": "residential",
        "maxweightrating:hgv": "24",
        "maxweightrating:hgv:condtitional": "none @ marked",
        "name": "Mikołaja Reja",
        "source:maxweightrating:hgv": "PL:sign_B-5-note"
      },
      "relations": [{
        "role": "",
        "rel": "4046118",
        "reltags": {
          "colour": "blue",
          "description": "Leśna trasa rowerowa, preferowany rower górski / Forest track, Mountain Bike preferred",
          "lcn_ref": "niebieski",
          "name": "Szlak Trójmiejski",
          "network": "rcn",
          "route": "bicycle",
          "type": "route"
        }
      }],
      "meta": {
        "timestamp": "2014-04-17T11:58:45Z",
        "version": "20",
        "changeset": "21747999",
        "user": "wojtas82",
        "uid": "729745"
      },
      "tainted": true
    },
    "geometry": {
      "type": "LineString",
      "coordinates": [[
          18.5024141,
          54.4354139
      ],[
          18.503622,
          54.4353485
      ],[
          18.5053714,
          54.4352858
      ]]
    }
  }]
};

var rower2 = L.geoJson(rower, {
  style: function (feature) {
    console.log(feature.properties.relations[0].reltags.colour);
    switch (feature.properties.relations[0].reltags.colour) {
      case 'blue':
        return {color: "#FF0000"};
      case 'red':
        return {color: "#0000FF"};
    }
  }
}).addTo(map);

map.fitBounds(rower2.getBounds());
body {
  margin: 0;
}
html, body, #map {
  height: 100%;
}