AlternateSprite.cs

using UnityEngine;

[System.Serializable]
public class AlternateSprite
{
    public Sprite AltSprite;
    public SpriteRenderer[] TargetRenderers;
    
    public void Activate ()
    {
        for (int i = 0; i < TargetRenderers.Length; i++)
            TargetRenderers[i].sprite = AltSprite;
    }
}