Silver (colour)
From Tardis Wiki, the free Doctor Who reference
Silver was a colour.
The leaves on Gallifrey's trees were bright silver. (TV: "A Desperate Venture", Gridlock)
The Cybermen were silver in colour. (TV: The Moonbase)
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)