Tim Kehoe has stained the whites of his eyes deep blue. He's also stained his face, his car, several bathtubs and a few dozen children. He's had to evacuate his family because he filled the house with noxious fumes. He's ruined every kitchen he's ever had. Kehoe, a 35-year-old toy inventor from St. Paul, Minnesota, has done all this in an effort to make real an idea he had more than 10 years ago, one he's been told repeatedly cannot be realized: a colored bubble.