Change 3mf loader's default color to white. (#22808)

examples/jsm/loaders/3MFLoader.js

@@ -1077,7 +1077,7 @@ class ThreeMFLoader extends Loader {
 			geometry.setIndex( new BufferAttribute( meshData[ 'triangles' ], 1 ) );
 			geometry.setAttribute( 'position', new BufferAttribute( meshData[ 'vertices' ], 3 ) );
 
-			const material = new MeshPhongMaterial( { color: 0xaaaaff, flatShading: true } );
+			const material = new MeshPhongMaterial( { color: 0xffffff, flatShading: true } );
 
 			const mesh = new Mesh( geometry, material );