How to use the @babylonjs/core.Color3 function in @babylonjs/core

model.meshes.map((mesh, index) => {
      let material = new StandardMaterial("kosh", scene);
      material.reflectionTexture = new CubeTexture("assets/textures/TropicalSunnyDay", scene);
      material.diffuseColor = new Color3(0, 0, 0);
      material.emissiveColor = new Color3(0.5, 0.5, 0.5);
      material.alpha = 0.2;
      material.specularPower = 16;

      // Fresnel
      material.reflectionFresnelParameters = new FresnelParameters();
      material.reflectionFresnelParameters.bias = 0.1;

      material.emissiveFresnelParameters = new FresnelParameters();
      material.emissiveFresnelParameters.bias = 0.6;
      material.emissiveFresnelParameters.power = 4;
      material.emissiveFresnelParameters.leftColor = Color3.White();
      material.emissiveFresnelParameters.rightColor = Color3.Black();

      material.opacityFresnelParameters = new FresnelParameters();
      material.opacityFresnelParameters.leftColor = Color3.White();

model.meshes.map((mesh, index) => {
      let material = new StandardMaterial("kosh", scene);
      material.reflectionTexture = new CubeTexture("assets/textures/TropicalSunnyDay", scene);
      material.diffuseColor = new Color3(0, 0, 0);
      material.emissiveColor = new Color3(0.5, 0.5, 0.5);
      material.alpha = 0.2;
      material.specularPower = 16;

      // Fresnel
      material.reflectionFresnelParameters = new FresnelParameters();
      material.reflectionFresnelParameters.bias = 0.1;

      material.emissiveFresnelParameters = new FresnelParameters();
      material.emissiveFresnelParameters.bias = 0.6;
      material.emissiveFresnelParameters.power = 4;
      material.emissiveFresnelParameters.leftColor = Color3.White();
      material.emissiveFresnelParameters.rightColor = Color3.Black();

      material.opacityFresnelParameters = new FresnelParameters();
      material.opacityFresnelParameters.leftColor = Color3.White();
      material.opacityFresnelParameters.rightColor = Color3.Black();

      default: () => new Color3(1, 1, 1),
    },

function onSceneMount (e) {
  const { canvas, scene } = e

  scene.clearColor = new Color3(0.5, 0.5, 0.5)
  var camera = new FreeCamera('camera1', new Vector3(0, 0.3, -0.7), scene)
  camera.speed = 0.01
  camera.minZ = 0.001
  scene.activeCameras.push(camera)
  camera.attachControl(canvas, true)
  var light = new HemisphericLight('light1', new Vector3(0, 1, 0), scene)
  light.intensity = 0.7
  var pbr = new PBRMetallicRoughnessMaterial('pbr', scene)
  pbr.environmentTexture = CubeTexture.CreateFromPrefilteredData('assets/textures/environment.dds', scene)
  var gridSize = 4
  for (var i = 0; i < gridSize; i++) {
    for (var j = 0; j < 10; j++) {
      var sphereMat = pbr.clone()
      sphereMat.metallic = 0.1
      sphereMat.roughness = (i / gridSize) / 3
      sphereMat.baseColor = Color3.White().scale(1 - (j / 10))

      default: () => new Color3(0.2, 0.2, 0.3),
    },

      default: () => new Color3(0, 0, 0),
    },