filterTransparentPolygons = (polygons, colorData) => {
	return polygons.filter(polygon => {
		const color = getColorByPos(polygonCenter(polygon), colorData);
		return !isTransparent(color);
	});
}
Filter polygons with transparent color
@param  {Array} polygons    Polygons array
@param  {Object} colorData  Color data
@return {Array}             Filtered polygons array