There were harsh lines of fatigue and urgency in his face but his tattered gray hat was off with a sweep.

从表情来看，军官已十分疲劳可又有极为紧迫的任务在身，不过他还是迅速地摘下了那顶破旧的军帽。

There's also this other term called a gray hat where they could be a IT admin during the day while moonlight as a black hat during the night.

还有另一个称为灰帽的术语，他们在白天担任 IT 管理员，而在晚上则是黑帽黑客。

Before he was many days old he was not only looking like a mouse but acting like one, too -- wearing a gray hat and carrying a small cane.

在他生下来后的很多天里，头上戴着一顶灰帽子，拄着一根小手杖的他，不仅样子像一只老鼠，行为方式也像。