View full lesson: http://ed.ted.com/lessons/history-s-d...\n\nWhen radium was first discovered, its luminous green color inspired people to add it into beauty products and jewelry. It wasn’t until much later that we realized that radium’s harmful effects outweighed its visual benefits. Unfortunately, radium isn’t the only pigment that historically seemed harmless or useful but turned out to be deadly. J. V. Maranto details history’s deadliest colors. \n\nLesson by J. V. Maranto, animation by Juan M. Urbina.