title: mapbox gl change icon color
body: <p>Is there a way to change a mapbox-gl-js icon-image color?</p>
  
  <p>This code taken from <a href="https://www.mapbox.com/mapbox-gl-js/example/geojson-markers/" rel="noreferrer">https://www.mapbox.com/mapbox-gl-js/example/geojson-markers/</a> won't change the marker color to red</p>
  
  <pre class="lang-javascript prettyprint-override"><code>map.addLayer({
      "id": "markers",
      "type": "symbol",
      "source": "markers",
      "layout": {
          "icon-image": "{marker-symbol}-15",
          "text-field": "{title}",
          "text-font": ["Open Sans Semibold", "Arial Unicode MS Bold"],
          "text-offset": [0, 0.6],
          "text-anchor": "top"
      },
      "paint": {
          "text-size": 12,
          "icon-color" : "#ff0000"
      }
  });
  </code></pre>
  
  <p>I've tried all the options listed in the official documentation</p>