Chestnut (colour)
From Tardis Wiki, the free Doctor Who reference
Chestnut was a dark shade of brown named after a nut.
The Fourth Doctor mentioned chestnut was one of the five colours of his scarf while listing pointless facts to defeat the Prolocture. (AUDIO: Babblesphere)
The Tenth Doctor wore a dark chestnut brown tie with a subtle flora woven pattern. (TV: The Christmas Invasion)
