Firefighters, law officers, and meat inspectors must be able to distinguish colors to do their jobs. Colorblind people have long been banned from these and other careers but improvements in technology are making it easier for them to get jobs. Changes in regulations and lobbying efforts are also opening up opportunities for the colorblind.
See "When Colorblindness Cramps Careers", Tanya Mohn, The New York Times, May 22, 2001