What does it mean to see a cold joke?

Mr. Beaver is a small animal in the advertisement of Colgate toothpaste. Children know a lot. In order to promote Mandarin among children, the original words are "Mr. Beaver, why are your teeth so white?" -Because I use Colgate herbal toothpaste. "To tell the truth, it's a bit far-fetched, but the world wonders, even Sister Furong can be red, and this kind of cold joke can naturally come out, ha ha.