private void shadeCountries() {
   for (Marker marker : countryMarkers) {
     // Find data for country of the current marker
     String countryId = marker.getId();
     if (lifeExpByCountry.containsKey(countryId)) {
       float lifeExp = lifeExpByCountry.get(countryId);
       int colorLevel = (int) map(lifeExp, 40, 90, 10, 255);
       marker.setColor(color(255 - colorLevel, 100, colorLevel));
     } else {
       marker.setColor(color(150, 150, 150));
     }
   }
 }
 private void shadeCountries() {
   for (Marker marker : coutryMarkers) {
     String coutryId = marker.getId();
     if (lifeExpByCountry.containsKey(coutryId)) {
       float lifeExp = lifeExpByCountry.get(coutryId);
       // now encode values as brightness (values range between 40-90)
       int colorLevel = (int) map(lifeExp, 40, 90, 10, 255);
       marker.setColor(color(255 - colorLevel, 100, colorLevel));
     } else {
       marker.setColor(color(150, 150, 150));
     }
   }
 }