A consumer is suing Mars Inc., the parent company ofSkittles, alleging that the rainbow-colored candy contains a “known toxin,” making it “unfit for human consumption,” according to the lawsuit. Attorneys for consumer Jenile Thames filed the lawsuit in the U.S. District Court for the Northern District of California on Thursday, alleging that the Skittles contained unsafe levels of titanium dioxide, according to USA Today. Titanium dioxide is used to produce that artificial rainbow coloring that covers each Skittles candy. In 2016, Mars Inc. announced its intention to remove titanium dioxide fr…