Greenback's end...

The end of the greenback is nigh! On October 9 a new and improved version of what has hitherto been affectionately known as the "greenback" will enter into circulation, but the new $20 note will not actually be green. The background is to be a shade of "subtle green, peach and blue". And that is by no means all: there are also plans for revamping the $50 and $100 bills.

Different colours will be used for different denominations, which, the Fed tells us, "will help everyone - particularly