public void LightAll()
{
for (int i = 0; i < objects.Length; i++)
{
    if(objects[i] != null)
    {
      var renderer = objects[i].GetComponent<SpriteRenderer>();
      if(renderer != null)
      {
       var alpha = renderer.color.a;
       renderer.color = new  Color(255,255,255, alpha);
      }
    }
}
}

for (var i = 0; i < objects.Length; i++) {

   if (objects[i] == null) continue;

   var renderer = objects[i].GetComponent<SpriteRenderer>();

   if (renderer == null) continue;

   renderer.color = new  Color(255,255,255, renderer.color.a);

  }