Rainbow Code


The Rainbow Codes were a series of code names used to disguise the nature of various British military research projects. They were mainly used by the Ministry of Supply from the end of the Second World War until 1958, when the ministry was broken up and its functions distributed among the forces. The codes were replaced by an alphanumeric code system, consisting of two letters followed by three digits.

History

During World War II, British intelligence was able to glean details of new German technologies simply by considering their code names. For instance, when they heard of a new system known as Wotan, Reginald Victor Jones asked around and found that Wotan was a one-eyed god. Based on this, he guessed it was a radio navigation system using a single radio beam. This proved correct, and the Royal Air Force was able to quickly render it useless through jamming.
Wishing to avoid making this sort of mistake, the Ministry of Supply initiated a system that would be entirely random and deliberately unrelated to the program in any way, while still being easy to remember. Each rainbow code name was constructed from a randomly selected colour, plus an noun taken from a list, for example:
While most colour and noun combinations were meaningless, some combinations produced real names, although quite unrelated to the project they designated. For example, "Black Maria" is also a nickname for a police van and the "Red Duster" is a nickname for the Red Ensign, the flag flown by British merchant ships. Some code names were not assigned through the official system, but created to sound like it. The Blue Yeoman radar is an example, an unofficial name created by combining the names of two other projects, Blue Riband and Orange Yeoman.
The names were mostly dropped with the end of the Ministry in 1959. Its functions were split between the War Office, the Air Ministry, and the newly created Ministry of Aviation, which was responsible for civil aviation. After the reorganization, projects were mostly named with randomly selected codes comprising two letters and three digits, e.g. BL755, WE.177. Rainbow codes, or at least names that look like them without being official, have occasionally been used for some modern systems; current examples include the Orange Reaper electronic support measures system and the Blue Vixen radar—the latter most likely so named because it was a replacement for the Blue Fox radar.

Projects

Black

Blue

Brown

  • Brown Bunny – original, unofficial name for Blue Peacock

Green

Indigo

Jade

Orange

Pink

  • Pink Hawk – early name for Fairey Fireflash missile. As this was a "watered down" version of the [|Red Hawk], and thus pink, it is an example of Rainbow Codes having some implied meaning, rather than their usual purely deliberately meaningless choice.

Purple

  • Purple Granite – nuclear weapon – see Green Granite
  • Purple Passion – sub-kiloton demolition mine project related to Violet Mist
  • Purple Possum – VX nerve agent

Red

  • Red Achilles – flamethrower kit for the CT 25 armoured carrier
  • Red Angel – air-launched anti-ship weapon or "special bomb"
  • Red Bacchus – mobile mixing plant for Red Vulcan flamethrower fuel
  • Red Beard – nuclear weapon
  • Red Biddy – infantry platoon anti-tank missile, cancelled 1953
  • Red Brick – experimental continuous-wave target illuminating radar
  • Red Cabbage – naval radar
  • Red Carpet – X-band radar jammer
  • Red Cat – air-launched nuclear stand-off missile cancelled 11/54.
  • Red Cheeks – inertially guided bomb based on the work of Tubby Vielle
  • Red Cyclops – flamethrower kit for the FV201 tank
  • Red Dean – large air-to-air missile
  • Red Devil – experimental blind bombing system using Green Satin and Red Setter radars together
  • Red Drover – airborne radar – see Avro 730
  • Red Duster – Bristol Bloodhound surface-to-air missile
  • Red Elsie – AP No. 8 anti-personnel mine, developed jointly with Canada.
  • Red Eye – An American general-purpose infra-red homing missile
  • Red Flag – free-fall nuclear bomb – 'Improved Kiloton Bomb' – WE.177
  • Red Flannel – experimental Q band H2S
  • Red Garter – Cossor ARI 5818 airborne tail warning radar for the Vulcan, did not enter service
  • Red Hawk – large air-to-air missile "downrated" to give Pink Hawk which became [|Blue Sky]
  • Red Heathen – early SAM project, became Red Shoes and Red Duster
  • Red Hebe – air-to-air missile, a replacement for [|Red Dean]
  • Red Hermes – FV3702 armoured fuel trailer for flamethrower tanks
  • Red Indian – analogue anti-aircraft fire control computer for Bofors L/70 gun.
  • Red King – two-barrel revolver cannon, developed alongside Red Queen. The name is likely not random, but instead a reference to its Oerlikon factory designation, RK, for Revolver Kanone.
  • Red Light – X band jammer for V Bombers, entered service as ARI 18146
  • Red Neck – airborne side-looking radar, tested on the Victor, a 40 foot long aerial under each wing. Flexing in flight corrupted the resolution. Cancelled 1962.
  • Red Planet – infantry platoon anti-tank missile
  • Red Queen – rapid fire 42 mm revolver cannon anti-aircraft gun
  • Red Rapier, Blue Rapier missiles – see UB.109T
  • Red Rose – short-range, battlefield nuclear missile for the British Army – English Electric – later known as Blue Water; cancelled 1962
  • Red Sea (AA) – the AA predictor designed for use with the Green Mace automatic AA gun
  • Red Setter – experimental side-looking radar for V bombers
  • Red Shoes – see English Electric Thunderbird
  • Red Shrimp – ARI 18076 airborne high-band jammer fitted to Victor and Vulcan
  • Red Snow – nuclear weapon physics package – fitted to [|Yellow Sun Mk2] and Blue Steel
  • Red Steer – EKCO ARI 5919/ARI 5952 airborne tail warning radar – development of AI 20 [|Green Willow] – fitted to Victor and Vulcan. The name likely refers to Jerry Steer at the RRE
  • Red Ticket – associated with AI 17 radar
  • Red Top – air-to-air missile developed from the Firestreak Mk 4
  • Red Tulip – phase coherent radar Moving Target Indicator
  • Red Vulcan – flamethrower fuel mixture

Violet

Yellow

  • Yellow Anvil – nuclear artillery shell warhead
  • Yellow Aster – H2S Mk 9A bombing radar, fitted to V bombers
  • Yellow Barley – radar warning receiver
  • Yellow Duckling – infra-red submarine detector
  • Yellow Feather – missile seeker
  • Yellow Fever – fire control system for the Bofors L/70 anti-aircraft gun, comprising a Blue Diamond radar and a Red Indian analogue computer
  • Yellow Gate – Loral ESM for E-3D Sentry and Nimrod MR.2
  • Yellow Jack – Orange Pippin's radar component
  • Yellow Lemon – Doppler-navigation system for naval aircraft. Valve-based precursor to the transistorised Blue Jacket.
  • Yellow River – mobile tactical control radar for Bristol Bloodhound – a.k.a. AMES Type 83
  • Yellow Sand – anti-ship missile, possibly a precursor to [|Green Cheese]
  • Yellow Sun – nuclear weapon casing
  • Yellow Temple – nuclear-armed SAGW development of Red Shoes
  • Yellow Tiger – Target illuminating radar used with the Thunderbird missile
  • Yellow Veil – ALQ-167 pod for Royal Navy Lynx

Non-Rainbow codes

Several British military-related terms have a similar "colour" format to Rainbow Codes, but are not true examples since they do not refer to classified research projects and/or were adopted long after Rainbow Codes went out of use. Others are entirely unofficial nicknames. These include:
  • Black Banana – unofficial nickname for the Blackburn Buccaneer. The name "ARNA" was submitted to a Blackburn in-house naming competition. It was only when "Blackburn ARNA" was said out loud that the joke became clear. The initial service aircraft were painted Anti-flash white and were thus nicknamed "Peeled Nanas".
  • Black Beacon – The Orfordness Rotating Wireless Beacon, known simply as the Orfordness Beacon or sometimes the Black Beacon, was an early radio navigation system
  • Blue Circle – sardonic name for concrete ballast for Buccaneer while awaiting Blue Parrot radar. Also used for Sea Harrier ballast in place of Blue Fox radar, and Tornado F.2 ballast. From the Blue Circle cement company.
  • Blue Eric – improvised I band ECM jammer against the Fledermaus anti-aircraft gun control radar used by Argentine forces during the Falklands War. Installed in the Harrier GR.3's starboard 30mm gun pod.
  • Blue Yeoman – unofficial name for an experimental radar made from components of the Blue Riband and Orange Yeoman
  • Green Goddess – colloquial name for Civil Defence fire pump
  • Green Meat – a 'spoof' SAM programme reported in the 1976 RAF Yearbook
  • Green Parrot – unconfirmed low yield nuclear weapon mentioned in a 1981 New Statesman article by Duncan Campbell who later claimed that it was "probably" a copy of the US B57 nuclear bomb. The WE.177 has incorrectly been referred to as the Green Parrot by some authors. However Green Parrot was a NATO codename for the Soviet PFM-1 anti-infantry mine. Green Parrot was also the term for an admiral's barge, traditionally with a green-painted hull.
  • Green Porridge – RAF aircrew nickname for green-tinted H2S bombing radar display PPI image in Valiant, Victor & Vulcan
  • Red Arrows – RAF display team
  • Red Devils – Parachute Regiment display team
  • Red Slab – joke name for a large ballast weight replacing the nose radar in Avro Vulcan XH558 in its return to flight as a civil display aircraft.
  • Violet Fire – Ultraviolet light fire detection system for Concorde engine bays.

In popular culture

An allusion to the Rainbow codes was made in the title of the 1961 Alistair MacLean Cold War novel The Dark Crusader, even more so in the American edition's title The Black Shrike. Both names were based on Blue Streak ; the title was of a fictional solid-fueled ICBM which was the object of a covert theft operation at an isolated Fijian test site.