docs: public static void setPreferredRoadColor(RoadType roadType, Integer color) {
  		final RoadType rt = roadType == null ? RoadType.OTHER : roadType;
  		final Preferences prefs = Preferences.userNodeForPackage(RoadNetworkLayerConstants.class);
  		if (prefs != null) {
  			if (color == null || color.intValue() == DEFAULT_ROAD_COLORS[rt.ordinal() * 2]) {
  				prefs.remove("ROAD_COLOR_" + rt.name().toUpperCase()); //$NON-NLS-1$
  			} else {
  				prefs.put("ROAD_COLOR_" + rt.name().toUpperCase(), Integer.toString(color.intValue())); //$NON-NLS-1$
  			}
  			try {
  				prefs.flush();
  			} catch (BackingStoreException exception) {
  				//
  			}
  		}
  	}