为什么法国还有一个别名Les Bleus?

不是指法国,而是指法国国足队或法国国家橄榄球队,因为这两支球队主场队服的颜色都是蓝色,中文里面没有对应的译法,硬译的话可以叫“蓝色军团”,不过会让人误以为是意大利队.
见维基：
Les Bleus is often used in a French sporting context,and in particular may refer to:
France national football team
France national rugby union team
Les Bleus (TV Show),M6 French series