I think this, like Moore's foie gras proposal, means that Chicago aldermen don't have enough to do when it comes to governing the city, so they're mixing themselves up in areas in which they have no expertise. This is an issue for the FDA or, at the very least, the state department of agriculture.
Makes a nice headline for Burke, though, doesn't it? The alderman who cares about your health. Does he care what this proposal may do to the price of meat in the city if retailers have to go outside their regular suppliers to get untreated meat? Is he also going to ban special lighting and pink-tinted plastic wrap?
The color of meat is not a reliable indicator of freshness under any circumstances.