I think he/she is talking about the plastic bags instead of white they are tinted gray. Which white can do if the color isn't mixed properly. I see it with paint all the time.
It also happens with recycled plastic when other colors get mixed into the grind. The other problem with recycled plastic bags is that they're weaker and more prone to tearing.
Sorry Karen we have what we have, if you had brought your own bags this wouldn't be an issue. Or you can just take your items without bags - problem solved!