ColorPropertySetter.cs

using UnityEngine;

public class ColorPropertySetter : MonoBehaviour
{
    //The color of the object
    public Color MaterialColor;

    //The material property block we pass to the GPU
    private MaterialPropertyBlock propertyBlock;
    
    // OnValidate is called in the editor after the component is edited
    void OnValidate()
    {
        //create propertyblock only if none exists
        if (propertyBlock == null)
            propertyBlock = new MaterialPropertyBlock();
        //Get a renderer component either of the own gameobject or of a child
        Renderer renderer = GetComponentInChildren<Renderer>();
        //set the color property
        propertyBlock.SetColor("_Color", MaterialColor);
        //apply propertyBlock to renderer
        renderer.SetPropertyBlock(propertyBlock);
    }
}