Gunmetal (colour)
From Tardis Wiki, the free Doctor Who reference
Gunmetal was a dark shade of grey.
When the Third Doctor encountered a new Dalek command structure, Dalek drones were identified by their gunmetal grey casings. (TV: Day of the Daleks, Frontier in Space, Planet of the Daleks, Destiny of the Daleks) The Renegade Daleks had gunmetal and black casings. (TV: Resurrection of the Daleks, Revelation of the Daleks, Remembrance of the Daleks)
The Master wore gunmetal grey cargo trousers when on hiding. (TV: The End of Time)
