The Olympic flag has a plain white background with no border. In the centre are   five rings forming two rows of three rings above and two below. The rings of the   upper row are, from left to right, blue, black and red. The rings of the lower row   are yellow and green.     The rings are thought to symbolise the five continents: Europe, Asia, Africa,   Australia and America. It is widely believed that the colours of the rings were   chosen because at least one of them can be found in the flag of every nation,   though this has never been confirmed as the intention of the designer.     The flag was presented by Games founder Baron de Coubertin at the 1914   Olympic Congress, celebrating the 20th anniversary of the founding of the IOC.   It was first flown in Alexandria, Greece, but made its Olympic debut at the 1920   Antwerp Games. This well-worn flag was finally retired after the 1984 Games,   and a new one flown at the 1988 Seoul Games.     At the Closing Ceremonies of the Olympic Games, the mayor of the current   Olympic host city presents the flag to the mayor of the next host city. The flag   is then kept in the town hall of the host city until the next Olympic Games.