It may be useful to you as a consumer as a way of avoiding sugar, fat, or whatever it is you think is unhealthy. Even that is dubious. But it's completely usele

It may be useful to you as a consumer as a way of avoiding sugar, fat, or whatever it is you think is unhealthy. Even that is dubious. But it's completely useless scientifically. There's no theoretical link between brightly colored boxes and weight gain. As you just admitted, that's only a proxy for something else you care about.