Captain Scarlet, as the main protagonist, is one of the most developed characters in the series. His real name is Paul Metcalfe. He has black hair and blue eyes, speaks with an English accent and is said to be from Winchester in Hampshire, England. He was born on 17 December, 2036. He is not unfamiliar with gambling and drinking and in the episode Special Assignment plays, and loses heavily at, roulette. In the episode Flight 104, Captain Scarlet expresses a preference for steak with all the trimmings.
Captain Scarlet and the Mysterons, often referred to as Captain Scarlet, is a 1960s British science-fiction television series produced by the Century 21 Productions company of Gerry and Sylvia Anderson, John Read and Reg Hill. First broadcast on ATV Midlands between September 1967 and May 1968, it has since been transmitted in more than 40 other countries, including the United States, Australia, New Zealand and Japan. Combined with scale model special effects, characters are presented as marionette puppets in a filming technique that the Andersons dubbed Supermarionation , a technology that incorporated internal solenoid motors as a means of producing mouth movements synchronised with pre-recorded dialogue.
With Anderson serving chiefly as executive producer, the majority of the writing input for Captain Scarlet was provided by Tony Barwick, who had previously written for the short-lived second season of Thunderbirds. Originally given the role of script editor, Barwick went on to pen 18 of the 32 episodes himself, and was also often required to make substantial changes to other writers' work. While discussing his approach to writing episodes in a 1986 interview, he drew parallels between the premise and characters of Captain Scarlet and those of Thunderbirds, suggesting, for example, that the Spectrum Organisation was similar to International Rescue and that the character of Captain Black was like the earlier recurring villain from Thunderbirds, The Hood.
The regular puppet cast of Captain Scarlet was the largest of all the Anderson Supermarionation series. While earlier productions had emphasised the benefits of futuristic technology, for Captain Scarlet it was decided to develop and deepen the cast of characters. Further to the enhanced realism of the puppet design, voice roles for Captain Scarlet were, as opposed to Thunderbirds and other predecessors, also intended to be less caricatured. Anderson biographers Simon Archer and Marcus Hearn note that, between Thunderbirds and Captain Scarlet, a proliferation of English-accented voices altered the sound of the Supermarionation production and its impression on the viewer.