JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://leafletjs.com/dist/leaflet.js"></script>
<link rel="stylesheet" href="http://leafletjs.com/dist/leaflet.css">

<div id="map" style="width: 600px; height: 400px"></div>

JavaScript

var map = L.map('map').setView([47.73193447949174,11.865234375], 12);

		L.tileLayer('https://{s}.tiles.mapbox.com/v3/ustroetz.hied1fh3/{z}/{x}/{y}.png', {
			attribution: 'Map data © <a href="http://openstreetmap.org">OpenStreetMap</a> contributors'
		}).addTo(map);

		var yourGeoJSON = [ 
{ "type": "Feature", "properties": { "id": 2, "elevation": 50 }, "geometry": { "type": "LineString", "coordinates": [ [ 11.836395263671875, 47.75317468890147 ], [ 11.865234375, 47.73193447949174 ] ] } },
{ "type": "Feature", "properties": { "id": 1, "elevation": 750 }, "geometry": { "type": "LineString", "coordinates": [ [ 11.865234375,47.73193447949174 ], [ 11.881027221679688, 47.700520033704954 ] ] } },
{ "type": "Feature", "properties": { "id": 0, "elevation": 1700 }, "geometry": { "type": "LineString", "coordinates": [ [ 11.881027221679688, 47.700520033704954 ], [ 11.923599243164062, 47.706527200903395 ] ] } },
{ "type": "Feature", "properties": { "id": 0, "elevation": 3000 }, "geometry": { "type": "LineString", "coordinates": [ [ 11.923599243164062, 47.706527200903395 ], [ 11.881027221679688, 47.700520033704954 ], ] } }
];


function getColor(x) {
  return x < 500     ?    '#bd0026':
         x < 1000     ?   '#f03b20':
         x < 1500     ?   '#fd8d3c':
         x < 2000     ?   '#fecc5c':
                          '#ffffb2' ;
};
 
var addLayer = L.FeatureGroup.prototype.addLayer;
L.GeoJSON.prototype.addLayer = function (layer) {
    console.log('geojson-addlayer');
    return addLayer.call(this, layer);
};
 
		L.geoJson(yourGeoJSON, {
			style: function (feature) {
  				return {
   				 "color": getColor(feature.properties.elevation),
   				 "opacity": 1,
  				}}
		}).addTo(map);