The paragraph preceding what you quoted also had this to say: "Cadmium sulfide is not very toxic (LD50 > 5000 mg/kg) when used as a pigment, although acute exposure to cadmium vapors from welding is harmful." In the case of these workers there are many details missing (whether they're using cadmiums, whether there is more exposure risk) but at least here in the US, all cadmiums I own are real and come with datasheets such as the one below:
http://d4of2brjuv1jo.cloudfront.net/assetfiles/f4fd8b8f-8fb5...
Azo colors, from manufacturers I am familiar with anyway, name their products as such ("Azo Yellow" instead of "Cadmium Yellow").
http://d4of2brjuv1jo.cloudfront.net/assetfiles/bad43b91-5026...
Regarding CSS color names, I would hope that anyone who actually recognizes the word cadmium would be aware that there pixel is not suddenly made of zinc and that their seagreen background has not suddenly become saltwater. Now if it were the other way around, i.e. the names had always been arbitrary and suddenly someone decided it would be a great way to stick hazardous chemicals into things..!