Good question, and no they don’t. Changing the orb color so much was just an example, typically compositing tasks are less drastic. In the end I’d say compositing is about achieving artistic preference rather than physical correctness. In other words if you (or you artistic supervisor/director) want the orb to purple, who will notice the wrong reflections? Is it important enough to re-render? If it’s not noticeable enough, might as well leave it ‘wrong’.
