Silver (colour)
From Tardis Wiki, the free Doctor Who reference
Silver was a light shade of grey named after the substance.
The leaves on Gallifrey's trees were bright silver. (TV: "A Desperate Venture", Gridlock)
The Eighth Doctor wore a double breasted waistcoat of silver paisley-brocade. (TV: Doctor Who)
Some Daleks had silver casings with blue globes. (TV: The Daleks, The Dalek Invasion of Earth, etc.)
The Cybermen were silver in colour. (TV: The Moonbase, The Invasion, Earthshock, Silver Nemesis, etc.)
The Tremas Master wore a silver waistcoat. (TV: Survival)
The Saurians had silver scales. (PROSE: Lords of the Galaxy)
Silver was a common colour for duct tape. (TV: The Woman Who Fell to Earth)