There are multiple options to achieve this:

• You could either use some default presets (see: theme: "lightblue-theme" option in readme file and the following file leaflet-elevation.css for some other default "*-theme" names).
• check out this example
• Or add the following lines for custom colors.

.elevation-control .area {
    fill: red;
}
.elevation-control .background {
    background-color: white;

These customizations are actually part of the leaflet-ui and can be toggled on/off using e.g. the following options:

var map = L.map('map', {
    center: [41.4583, 12.7059],  // needs value to initialize
    zoom: 5,                     // needs value to initialize
    mapTypeId: 'topo',
    mapTypeIds: ['osm', 'terrain', 'satellite', 'topo'],
    gestureHandling: false,     // zoom with Cmd + Scroll
    zoomControl: true,          // plus minus buttons
    pegmanControl: false,
    locateControl: false,
    fullscreenControl: true,
    layersControl: true,
    minimapControl: false,
    editInOSMControl: false,
    loadingControl: false,
    searchControl: false,
    disableDefaultUI: false,
    printControl: false,
});

Usually, when working with a js bundler like Vite or Webpack, you need to provide to this library the full path to some dynamically imported files from the srcFolder:

import './your-custom-style.css';
import 'leaflet/dist/leaflet.css';
import L from 'leaflet';
import '@raruto/leaflet-elevation/src/index.js';
import '@raruto/leaflet-elevation/src/index.css';

const map = L.map('map', {
    center: [41.4583, 12.7059]
    zoom: 5,
});

const controlElevation = L.control.elevation({
    // CHANGE ME: with your own http server folder (eg. "https://custom-server/public/path/to/leaflet-elevation/src/")
    srcFolder: 'https://unpkg.com/@raruto/leaflet-elevation/src/'
}).addTo(map);

// Load track from url (allowed data types: "*.geojson", "*.gpx", "*.tcx")
controlElevation.load("https://raruto.github.io/leaflet-elevation/examples/via-emilia.gpx");

• https://parcours.scasb.org/
• https://velocat.ru/velo/phpBB3/map.php
• https://plugins.qgis.org/plugins/track_profile_2_web/
• https://wordpress.org/plugins/os-datahub-maps/
• https://wordpress.org/plugins/extensions-leaflet-map/
• https://github.com/der-stefan/OpenTopoMap
• https://gpx.n-peloton.fr/
• https://walkaholic.me/map