Captain Scarlet (in-universe)

Captain Scarlet was a television series which starred a character of the same name.

The Twelfth Doctor once referred to UNIT's aircraft carrier Valiant as "Cloudbase", a key feature of the series. Osgood mistakenly thought the reference was from Thunderbirds, but was corrected by Colonel Ahmed. The Doctor then noted that he had met Sylvia Anderson. (TV: Death in Heaven)

Behind the scenes
Created by Sylvia and Gerry Anderson, Captain Scarlet and the Mysterons was a TV series produced by Century 21 Productions. Like Doctor Who it was initally created in the 1960s, with a revived series,, later broadcast in 2005.

The series also share narrative similarities with Torchwood, most notably in that they both feature immortal protagonists (Captain Scarlet and Captain Jack Harkness) employed by security organisations dedicated to defending the Earth from alien invasions. Like Torchwood, Captain Scarlet is also known for having a darker tone than its preceding series, such as Thunderbirds.
 * A small number of the original series' cast members have also appeared in Doctor Who, including Jeremy Wilkin, Martin King, and Shane Rimmer. Nigel Plaskitt, who appeared in New Captain Scarlet, has also made a guest appearance on the series.
 * Wayne Forester and Robbie Stevens who star in New Captain Scarlet have also appeared in Big Finish audio adventures. Glenn Wrage also appeared in five episodes, and Bruce Lawrence performed motion caption work for the series.
 * Crew members Derek Meddings and Peter Wragg worked on both the originial versions of Doctor Who and Captain Scarlet. A number of crew members have also worked on both revived series, including Alberto Montanes, Jenna Powell, Doug Sinclair, and Adam Rowland.
 * Doctor Who, Torchwood, and The Sarah Jane Adventures writer Phil Ford also wrote several episodes of Gerry Anderson's New Captain Scarlet.
 * The Second Doctor novel The Indestructible Man also contains many references to the original series. The title character, Captain Grant Matthews (named to reference Scarlet's likeness to Cary Grant and being voiced by actor Francis Matthews), was reconstructed by the Myloki (Mysterons) so that he couldn't die. As a member of the organisation PRISM (Spectrum), the colour-coded officer's uniform assigned to him was scarlet. The war with the Myloki is started by Captain Karl Taylor (Captain Black) who is recreated as a Myloki agent.