In fact, from Ale's point of view, this could be a blue hat.

事实上,从艾尔的角度看,这很有可能是顶蓝色的帽子

耶鲁公开课 - 博弈论课程节选

But Ale does not know that Kaj knows that he is wearing a blue, a pink hat, and Kaj does not know that Ale knows that Kaj is wearing a pink hat.

但艾尔不知道卡佳知道他戴着粉色帽子,卡佳也不知道艾尔知道,卡佳戴着粉色帽子

耶鲁公开课 - 博弈论课程节选