Leaflet polyline is not displayed with custom color

I'm working on a project and I'm using Leaflet. From an object list extracted from the DB, I can currently display markers with custom icons. Now I'm working to display polylines from data I got in DB. With Javascript, I get the list and I arrive to display polylines but they are all blue where I want them to have differents colors depending on a property of the polyline.

var geoJsonFluxMatiere = {
    'type': 'FeatureCollection',
    'features': []
};
for (indexfluxMatiere = 0; indexfluxMatiere < listeFluxMatiere.length; indexfluxMatiere++) {
    var tableauFluxMatiere = {
        type: 'Feature',
        properties: {
            'id': listeFluxMatiere[indexfluxMatiere].idFluxMatiere,
            'fluxPrimaire': listeFluxMatiere[indexfluxMatiere].fluxPrimaire
        },
        geometry: {
            'type': 'LineString',
            'coordinates': [
                [listeFluxMatiere[indexfluxMatiere].posXDepart, listeFluxMatiere[indexfluxMatiere].poxYDepart],
                [listeFluxMatiere[indexfluxMatiere].posXArrivee, listeFluxMatiere[indexfluxMatiere].posYArrivee]
            ]
        }
    }
    geoJsonFluxMatiere['features'].push(tableauFluxMatiere);
}

var layerFluxMatiere = L.geoJson(geoJsonFluxMatiere, {
    pointToLayer: function (feature, latlng) {
        if(feature.properties.fluxPrimaire == true){
            var polylineFluxMatiere = new L.polyline(
                feature.geometry.coordinates,
                {
                    color: 'red',
                }
            );
        }else{
            var polylineFluxMatiere = new L.polyline(
                feature.geometry.coordinates,
                {
                    color: 'green',
                }
            );
        }
        return polylineFluxMatiere;
    },
}).addTo(map);

Coordinates are ok and the polylines are displayed where they have to but it's like color's parameter is ignored.
Did I do something wrong ?
By the way, I'm sorry for my english if it is not perfect. Thank you !

Raphaël