Parent and childred not changing color

Unity Engine
1

I got this code on my parent but, it is not changing any color and the childred aint chaning to.
First I got a error that he couldnt not find any renderer on the object but the script is trying to acces it.

gameObject.GetComponent<Renderer> ().material.color = Color.green;
2

This bit of code is in a script attached to the parent? Does the Parent actually have a Renderer attached to it? Does the child(ren) of this parent GameObject have some kind of Renderer attached to them ?

If the only the child has a Renderer(Mesh,sprite, whatever) attached to it you can use this code to change it from the parent:

void Start()
    {
        GetComponentInChildren<Renderer>().material.color = Color.green;
    }

Note: this will only get the first renderer it finds in all the children. You can use GetComponentsInChildren (notice the s) to get all the renderers of all the children but then you need to save it to a Renderer[ ] variable. and access it through a for loop or foreach iteration

3

He is not even changing the color of the main object, weird.