Purple

Purple was a colour. According to the Twelfth Doctor, it was the colour of death. (TV: The Woman Who Lived)

The Thin Purple Arc was one of two epochs in the lives of the residents of the planet Fragrance. It was the time from a person's birth to when they fell in love. (AUDIO: The Fragile Yellow Arc of Fragrance)

Celery turned purple in the presence of gases in the Praxis range of the spectrum. One of the reasons the Fifth Doctor wore a stalk of celery in his lapel was to detect such gases. (TV: The Caves of Androzani)

The second Dalek Emperor of the New Dalek Paradigm had a purple casing. (GAME: The Eternity Clock)

In comparison to other colours like red or black, purple and yellow were inferior psychological triggers in humans. As such, a purple Eye of Eternity never appeared in Through the Eye of Eternity. (PROSE: The Book of the War)

The Eighth Doctor kept a purple Volkswagen Beetle in an alcove in his TARDIS, which he and Sam Jones drove on numerous occasions. (PROSE: Vampire Science, Longest Day, Seeing I)

Omphalos Prime was described by Leabie Forrester as a cold, purple world. (PROSE: Dependence Day) The planet Quinnis had a purple sea. (COMIC: A Religious Experience) The sky of an Earth-like planet was purple. (PROSE: Follow the Phantoms)

Ukkans were light pink-skinned humanoids with enlarged purple craniums, around a dozen purple tendrils on the head, and purple lips. (TV: Lost Library of Ukko) Equinoids resembled purple horses with yellow spots. (COMIC: Perceptions) The Xyz were various shades of purple. (PROSE: Not So Much a Programme, More a Way of Life) The Huducts had purple skin. (TV: Curse of Anubis)

Venusians had purple blood. (PROSE: Venusian Lullaby)

The Thirteenth Doctor expressed a fondness for the colour purple. (TV: Arachnids in the UK)

The War Doctor wore an eggplant purple scarf. (COMIC: The Lost Dimension)

Since meeting Clara Oswald, the Eleventh Doctor wore a single breast frockcoat of eggplant purple cashmere. (TV: The Bells of St. John, Cold War, The Name of the Doctor, The Day of the Doctor, The Time of the Doctor, etc.)

When inhabiting the body of Rose Tyler on New Earth, the Lady Cassandra removed her jacket to show off the purple patchwork blouse Rose was wearing underneath. (TV: New Earth)

Donna Noble wore a purple toga during her time on Pompeii. (TV: The Fires of Pompeii)

Kaled s such as Davros own purple flesh. (TV: The Stolen Earth)

The Master wore a purple frockcoat. (TV: Spyfall, Ascension of the Cybermen|The Timeless Children)

The Saurians had huge purple eyes. (PROSE: Lords of the Galaxy)