WASHINGTON-The newly redesigned $50 bills will start being circulated Sept. 28, the Federal Reserve and the Bureau of Engraving and Printing announced last week. The new currency features subtle background colors of blue and red, images of a waving American flag and a small metallic silver-blue star. Financial institutions and businesses should begin their final preparations for the new notes, the Fed and the Bureau warned. Some may just need to train employees on how to use the new built in security features, while others may need to make technical adjustments to ATMs and other machines. "The enhanced security features in this series of notes help ensure that U.S. currency will continue to represent the trust, value and confidence that people all over the world have grown to rely on and expect," Fed Governor Mark W. Olson said. "As always, all new notes will co-circulate with the older designs. All notes are good for good." "The objective of the new currency program is a safer, smarter and more secure currency and its smooth transition into daily commerce," Tom Ferguson, director of the Bureau, said. "To that end, we have been working with the appropriate machine manufacturers for nearly two years to ensure they have the information they need to make their equipment compatible with each newly redesigned note that is introduced into circulation." While the colored background itself is not a security feature, it does make the design more difficult to duplicate. There is also a watermark, security thread, and color-shifting ink. The redesigned $50 note is the second in the Series 2004 new currency designs after the $20, which was released in October 2003. A new $100 bill is also planned. A decision is still pending on whether the $10 and $5 notes will be redesigned, but the $1 and $2 designs will not change.