Emerald (colour)
From Tardis Wiki, the free Doctor Who reference
Emerald was a shade of green named after a certain gemstone.
Ace wore an emerald t-shirt under a black cardigan. (TV: Battlefield)
Bill Potts wore an emerald velvet coat during a visit to the 1814 frost fair. (TV: Thin Ice)
The Third Doctor wore a blazer of emerald velvet. (TV: The Monster of Peladon)
The Master wore an emerald cravat when posing as 'the other Doctor'. (AUDIO: Dominion)