奥运五环，为什么是五种颜色？

The Olympic flag has five rings. 奥运旗帜上，有五个圆环。 They are blue, yellow, black, green and red. 颜色是蓝、黄、黑、绿、红。 The rings stand for five continents. 五环代表世界五大洲。 They are linked together as one. 它们环环相扣，代表团结。 Every national flag has one of these colors. 当年各国国旗，至少含其中一色。 On a white background, it is easy to read. 配着白底，这面旗干净又好认。