Can't get children/Color not part of material

So I have a 3d game with a player that consists of an empty object with three children, one black engine and two body parts that need to change color.

using UnityEngine;
using System.Collections;

public class Collection : MonoBehaviour
{


    public Transform tForm;
    public GameObject gObject;
    private bool isGreen = false;
    private bool isRed = false;

    void OnTriggerEnter(Collider other)
    {
        //green
        if (other.gameObject.tag == "GreenCube")
        {
            other.gameObject.SetActive(false);
            isGreen = true;

        }
        //red
        if (other.gameObject.tag == "RedCube")
        {
            other.gameObject.SetActive(false);
            isRed = true;
        }
    }

    private Color childColorGreen;
    private Color childColorRed;



    public void ChangeColor ()
    {
        childColorGreen = new Color(0, 0, 1, 1);
        childColorRed = new Color(1, 0, 0, 1);
        
        if (isGreen == true)
        {
            gObject.FindComponentsInChildren<Material.Color>() = childColorGreen;
        }

        if (isRed == true)
        {
            gObject.FindComponentsInChildren<Material.Color>() = childColorRed;
        }
    }

}

Also, how do I get specific child? I need two child from “Player;” I need “Body” and “Front.”

Try something like this…

transform.Find("Body").gameObject.GetComponent<Material>().Color = childColorGreen;

Same idea for Front.

-Larry