talk until one is blue in the face.它的意思是“交谈到脸色都变了”，暗含的意思是说某人谈话谈个不停，一直到非常疲惫,但却没有达到应有的效果。
朋友们可能观察到，当人们谈话谈得太多时，有时连呼吸都调整不过来，这时就有可能导致脸变色，所以当有人长时间的谈论过后，人们就会用“blue in the face”来描述他。
Example 例句：
Sally talked with that boy until she was blue in the face, but the boy still did what he wanted.
Sally与那个男孩谈话谈到脸色都变了，但这男孩仍然我行我素。
