DisableToggleBG.cs

using UnityEngine;
using UnityEngine.UI;

public class DisableToggleBG : MonoBehaviour {

	Image cr;
	void Awake () {
		cr = GetComponent<Image>();
		GetComponentInParent<Toggle>().onValueChanged.AddListener((state) => {OnParentToggleChange(state);});
	}

	void OnParentToggleChange(bool state){
		cr.enabled = !state;
	}
}