The Olympic Rings, the symbol of the modern Olympic Games, is composed of five interlocking rings, colored blue, yellow, black, green, and red on a white field. It was originally designed in 1912 by Baron Pierre de Coubertin, the founder of the modern Olympic Games. The colors (including the white background) also represented at least one color on all national flags of the world at that time. The 1914 Olympic Congress had to be suspended due to the outbreak of World War I, but the symbol (and flag) were later adopted. They would first officially debut at the Games of the VII Olympiad in Antwerp, Belgium in 1920. The five rings represent the five (inhabited) continents: Europe (blue), Asia (yellow), Africa (black), Oceania (green) and the Americas (red).
Drawn by User:Pumbaa80; dimensions and colors taken from http://www.southyorkshire.nhs.uk/london2012/resources/LDN2012%20Brand%20Guidelines.pdf
Original author: Pierre de Coubertin (1863-1937)