How to set color attribution to GLTF model

Questions
2

How about storing the original color value in a custom property of Material.userData? In this way, you can easily connect the old color value with the respective material. So instead of using a typed array, you do this:

const material = sceneObject.children[0].children[i].material;
material.userData.color = material.color.clone();

If you want to restore the color value, do this:

material.color.copy( material.userData.color );