Green

Green was the official colour of mourning in Perfugium, as it symbolised death and a return to nature. (AUDIO: Master) and the universal colour for medicine. (COMIC: A Confusion of Angels)

It sat between blue and yellow on the visible spectrum. (TV: Sky)

Verdant/forest green were two names for a certain shade of green. (PROSE: Enter Wildthyme)

Amy Pond wore a scoop collar top done in green (TV: The Lodger)

Bill Potts wore an emerald green velvet overcoat when visiting the 1814 frost fair (TV: Thin Ice)

Toshiko Sato wore a green blouse (TV: Out of Time).

Doctor Olivia Steele wore a pale green blouse underneath a white lab coat. (PROSE: Exodus Code)

The Master's eighteenth incarnation wore a dark green shirt up to his death, (TV: World and Enough|The Doctor Falls)

Time Lords of the Arcalian Chapter wore green ceremonial robes. (TV: The Deadly Assassin)

Sontarans had green blood. (TV: The Two Doctors, The Last Sontaran; AUDIO: The Heroes of Sontar)

Skaro's life including Kaleds own green blood (AUDIO: The Juggernauts)

Many species had green skin, including Alpha Centaurans, (TV: The Curse of Peladon) Etydions, Foamasi, Ice Warriors, (TV: Cold War) Jadeans, Jagaroth, (TV: City of Death) Kleptons, Primitives, Rutans, (GAME: The Gunpowder Plot) Silurians, (TV: The Hungry Earth) Swampies, (TV: The Power of Kroll) Urbankans, (TV: Four to Doomsday) Vinvocci (TV: The End of Time) and Watermen. (COMIC: Dr. Who Meets the Watermen) Infant Chimerons (TV: Delta and the Bannermen) and larval Wirrn (TV: The Ark in Space) were also green.

Historians who had been allowed access to the "Monster Vaults" of the databanks in the Doctor's TARDIS observed that the Abzorbaloffs were bright green. (PROSE: The Monster Vault, TV: Love & Monsters)

Nardole noted that, while he had been blue at one point, he had never been green. (COMIC: A Confusion of Angels)

Stahlman's ooze was green. (TV: Inferno) The waste from Global Chemicals' oil-refining process was green. (TV: The Green Death) The sky of an Earth-like planet was green, (PROSE: The Sour Note) as was the sky of Arcopolis. (PROSE: The Eyeless)

During the Middle Ages, green was associated with witches and was considered unlucky. (PROSE: Wolfsbane)

Green Daleks were at the Gallifreyan warship Starbane. (GAME: The Doctor and the Dalek)

In Through the Eye of Eternity, the Green Eye of Eternity generally symbolised that the week's episode would concern ecological themes. (PROSE: The Book of the War)In an alternate timeline in which the First Doctor spent three months on Urbinia, his friend, Professor Feedlam discovered a new colour which was "a little bit green and a little bit black", creating "a sort of mauve". (AUDIO: Daughter of the Gods) A poster for Shrek featured Shrek, who had green skin, and a woman with red hair wearing a green dress. (TV: Dead Man Walking)

Instead of the typical silver, the Cyberon drug produced by the Cyberwolf Abigail was green. (PROSE: A Worthy Successor)

Behind the scenes
In the comic adaptation of the film Dr. Who and the Daleks, the police box-shaped TARDIS is erroneously coloured green as opposed to TARDIS blue.