Red

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Red was a colour at the opposite end to violet on the visible spectrum. It was situated after yellow and orange. (TV: Sky) Red was used by humans, in the form of red alerts, to indicate danger. The Ninth Doctor said non-humans regarded it as "camp". (TV: The Empty Child)

The Tenth Doctor referred to Mars as the "red planet". (TV: The Waters of Mars)

On Gallifrey, pastures of red grass stretched far across the slopes of Mount Perdition. (TV: The End of Time)

Racnoss, (TV: The Runaway Bride) Blowfish, (TV: Kiss Kiss, Bang Bang) Zocci, (TV: Voyage of the Damned) Posicarians (TV: Mindwarp) and Eve's species had red skin. (TV: Sarah Jane's Alien Files episode 2)

Rarely, red was an eye colour. Ood would gain red eyes whilst being possessed (TV: The Impossible Planet) or whilst having lost connection to the hive mind. (TV: Planet of the Ood) The Shadow Architect and Servant of the Shadow Proclamation also had red eyes, (TV: The Stolen Earth) as did Qataka's cybernetic body. (PROSE: Timewyrm: Genesys) During his imprisonment beneath a pyramid, Sutekh was known to his worshippers as "the Red God". It was said that those who entered his services would gain red, bloodshot eyes. (PROSE: Background)

]Several ranks of Daleks were identified by red casings, including the Red Daleks (COMIC: Eve of War) and Supreme Controllers. The Dalek Survival Guide, noting the presence of red coloration within Dalek ranks, concluded that red was indeed visible to the Daleks, instead theorising that "the misunderstanding" came from the possibility that early casings could only see in black and white. (PROSE: Dalek Survival Guide) A model of Supreme Dalek casing done in red was used before, during and after the Last Great Time War (AUDIO: Out of Time; COMIC: Ambush; TV: The Stolen Earth, The Magician's Apprentice) as was the New Dalek Paradigm's Drone Daleks. (TV: Victory of the Daleks; PROSE: The Only Good Dalek; GAME: City of the Daleks) The Scientist of the Dalek Time Squad was silver apart from its red dome, panels and globes. (PROSE: The Guide to the Dark Times) The leader of the Humanised Daleks, Alpha, had a red casing when he met the Eighth Doctor. (COMIC: Children of the Revolution)

Rose Tyler tended to wear red hoodies symbolizing her growth into heroism. (TV: World War Three, Dalek, The Long Game, Bad Wolf|Doomsday, Rise of the Cybermen; AUDIO: Cold Vengeance)

The Seventh Doctor had a red paisley handkerchief. (TV: Time and the Rani-The Greatest Show in the Galaxy)

The Third Doctor wore a green and red tartan cape when he and Jo Grant pursued the Master in his sixth incarnation. (TV: The Time Monster)

In Through the Eye of Eternity, the Red Eye of Eternity generally represented war or disaster, as portrayed through stock footage. After being served the wrong type of pizza, one fan drove his white Buick into a New York restaurant while screaming about the Eye being "on red"; in reality, the Eye pin he was wearing was green, but the man was colour blind. (PROSE: The Book of the War)

In 1893, Silurian Madame Vastra and her partners, Jenny and Sontaran Commander Strax, investigated "the Crimson Horror" — a mysterious condition leaving victims with red skin and preserved like statues. (TV: The Crimson Horror)

In the spring of 2007, while facing a Hoix with the Tenth Doctor, Rose Tyler threw a blue bucket of liquid at the Hoix. This was the wrong bucket, Rose had thought the Doctor said blue, but as the Doctor noted, he had said "not blue". This enraged the Hoix who chased Rose and the Doctor until Rose found the correct red bucket. Ursula Blake also frequently wore red glasses. (TV: Love & Monsters)

In slang

When Charlotte Pollard described Chief Stewart Weeks' nose as being "redder than Mr Lenin's pyjamas" on 4 October 1930, the Eighth Doctor disputed they were red; he claimed that they were a "sort of mauve" when the Doctor took a train with Lenin from Switzerland to Petrograd. (AUDIO: Storm Warning)

During the Cold War, the Americans and the British referred to their Russian and Chinese rivals as the "reds". (COMIC: The Good Soldier, TV: Dreamland, Children of Earth: Day One)

Welcoming Ashad and his Cybermen to the ruins of Gallifrey, the Spy Master promised that he would "roll out the red carpet", quipping that it was red because it was "drenched in the blood of [his] people". (TV: The Timeless Children)

Behind the scenes

• Strange to Tell... According to the Daleks, one of the non-narrative features from The Dalek World, gives more details as to why and how the colour red is invisible to the Daleks: when the colour-corrected electronic eye of the Dalek was constructed, red was not included in its perception range.
• James Johnson rendered a Time War-era Reconnaissance Dalek model which was featured on the cover of Gallifrey: War Room 1: Allegiance. Ahead of release, Johnson released a closer look at his designs, also clarifying that the accompanying text wasn't in any way official, and that he added it "just for fun". These bronze-type Daleks were equipped with Focusing Emitters and Deflector Globes.