Pink was a colour.
The Zero Room was pink. (TV: Castrovalva)
Rani Chandra occasionally wore pink. (TV: The Mark of the Beserker, The Temptation of Sarah Jane, The Mad Woman in the Attic, etc.)
Rose Tyler wore a pink t-shirt when she and the Ninth Doctor first met the Slitheen. (TV: Aliens of London, World War Three) She also wore a pink dress when she and the Tenth Doctor met the Wire. (TV: The Idiot's Lantern)
The Thirteenth Doctor wore a dark pink low collar shirt, (TV: Rosa) and a dark pink crew collar shirt. (TV: The Tsuranga Conundrum)
Sarah Jane Smith wore a pink tank-top when she met the Tenth Doctor. (TV: School Reunion)
Bill Potts wore a pink dress during her visit to the 1814 frost fair. (TV: Thin Ice)
Maria Jackson occasionally wore pink clothes. (TV: Eye of the Gorgon, etc)
The Happiness Patrol painted the Doctor's TARDIS pink. (TV: The Happiness Patrol)
Kalarians and Ukkans had light pink skin. (PROSE: The Final Sanction, TV: Lost Library of Ukko) Florence Finnegan recalled that the Child Princess of Padrivole Regency 9 had pink cheeks. (TV: Smith and Jones)
In the Mulifane system, pink was the traditional colour of fighting. (AUDIO: Forgotten Lives)
The snow on Nirvana was pink. (AUDIO: World Apart)
The Pink Cichorium was a near-extinct, beautiful, pink plant. The very last of its kind was tended daily by Irene, a botanist who lived alone on the mini-moon of Delphi. (COMIC: Borrowed Time)
Vaagon had a pink sun. Bubbleshake was pink, and came in pink cans. (PROSE: The Highest Science)
Raoul's partner imagined that "lesbian novelist" Iris "[lay] under a pink bedspread, like Barbara Cartland in Camden Town, a poodle either side and a typewriter on her lap". (PROSE: Hospitality)
Plasti-Discs were pink (PROSE: The Doomsday Manuscript)