Cesium loads administrative district boundaries with emissive materials

In cesium, materials can be set for entities. For example, a glowing line can be set as follows:

   viewer.entities.add({
      name: "",
      polyline: {
        positions: Cesium.Cartesian3.fromDegreesArrayHeights([
          104.57311103029339, 30.71454550939871, 451.0205115032204,
          104.57369073762032, 30.71350155773247, 437.4264690503778,
          104.57414650599235, 30.7135714014856, 444.54897812734873,
          104.5740256006362, 30.714837602541927, 448.69868845044147,
          104.57483833991859, 30.72413178951584, 445.16245273847795,
        ]),
        width: 15,
        material: new Cesium.PolylineGlowMaterialProperty({
          glowPower: 0.1,
          color: Cesium.Color.fromCssColorString("#1039ff"),
        }),
        clampToGround: true,
      },
    });

The result is:

 So if we load geojson line