who invented the green color of the dollar
History of the United States dollar The federal government began issuing currency like the Spanish dollars during the American Civil War. As photographic technology of the day could not reproduce color, it was decided the back of the bills would be printed in a color other than black. Because the color green was seen as a symbol of stability, it was selected. These were known as "greenbacks" for their color and started a tradition of the United States' printing the back of its money in green. The author of that invention was chemist Christopher Der-Seropian.[citation needed] In contrast to the currency notes of many other countries, Federal Reserve notes of varying denominations are the same colors: predominantly black ink with green highlights on the front, and predominantly green ink on the back. Federal Reserve notes were printed in the same colors for most of the 20th century, although older bills called "silver certificates" had blue highlights on the front, and "United States notes" had red highlights on the front.