The rings of blue, black, yellow, red and green, which make up one of the most recognized symbols in the world, traditionally represent the 5 different areas of the world involved in the Olympics (North and South America are considered one area, along with Africa, Australia, Asia and Europe).
The International Olympic Committee states that the Olympic Symbol reinforces the international component of the Olympic Movement as the meeting of athletes from around the world. According to the Olympic Charter, “The Olympic symbol expresses the activity of the Olympic Movement and represents the union of the five continents and the meeting of athletes from throughout the world at the Olympic Games.”
But the 6 colors, if you include the white background in the Olympic flag, were intended to represent the various colors seen on the flags of nations competing in the Games of Olympiads I, II, III, IV, and V. And historian David Young says it is likely that these rings could also symbolize the previous 5 Olympiads completed prior to 1914.