Can’t edit the color of them map using arcgis-core react

How can i change the color of the map? I used the @arcGIS/core for importing the map this is my code

this is my style.css

html,
body {
  padding: 0;
  margin: 0;
  width: 100%;
  height: 100%;
  font-feature-settings: "liga" 1, "calt" 0;
}

#root, .mapDiv {
  padding: 0;
  margin: 0;
  width: 100%;
  height: 500px;
  display: flex;
  letter-spacing: 0em;
  line-height: 1.55rem;
  background-color: gray;
}

this is my map code

....
import style from "../../component/css/style.css";


function MyMap(){
    const mapDiv = useRef(style);
    let cleanup;
    useEffect(()=> {
        if (mapDiv.current) {
            esriConfig.apiKey = ">>>>>>>><<<<<<<<";  
            const map = new Map({
                basemap: "arcgis-topographic" // Basemap layer service
                });
            const view = new MapView({
                map: map,
                container: mapDiv.current,
                center: [-118.805, 34.027], // Longitude, latitude
                zoom: 13, // Zoom level
                style: {
                    background: {
                      type: "color",
                      color: [192, 192, 192, 0.4]
                    },
                }
            })
            view.when((r)=> {
            }).then(()=> {
                mapDiv.current = view;
            });
        }
    },[])
    return (
        <div className="mapDiv" ref={mapDiv}>

        </div>
    )
}
export default MyMap

result

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from this line please dont read it from this line please dont read it
from this line please dont read it from this line please dont read it
from this line please dont read it