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.


During WWII, 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.[1]

Wishing to avoid making this sort of mistake, Ministry of Supply (MoS) initiated a system that would be entirely random and deliberately unrelated to the program in any way,[2] while still being easy to remember. Each rainbow code name was constructed from a randomly selected colour, plus an (often appropriate) noun taken from a list, for example:

While most colour and noun combinations were meaningless, some were real names, although quite unrelated to the project they designated. For example, "Black Maria" is also a name for a police van and the "Red Duster" is a name 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 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.[3] 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[4]—the latter most likely so named because it was a replacement for the Blue Fox radar.









  • Orange Blossom – Probably a deliberate mis-identification of the Orange Crop pods fitted to 1312 Flight Hercules aircraft, (Pod-mounted electronic support measures used on the Hercules – maybe).[citation needed]
  • Orange Cocktail – Experimental homing radar weapon from 1950s
  • Orange Crop Racal MIR 2 ESM system for Royal Navy Lynx and Royal Navy Sea King (HAS.5 onwards but not Mk 4 "Junglies", who had the Racal Prophet lightweight RWR fitted to some, or to the Royal Navy SAR) helicopters and some Royal Air Force Hercules aircraft.
  • Orange Harvest – S and X band warning receiver fitted to Shackletons
  • Orange Herald – large boosted fission nuclear warhead, tested at Operation Grapple in 1957.
  • Orange Nell – short-range surface-to-air missile (SAGW)
  • Orange Pippin – Ferranti, anti-aircraft, fire-control radar
  • Orange Poodle – low altitude, OTHR (Over-the-Horizon) early-warning radar – abandoned
  • Orange Putter – ARI 5800 airborne passive radar warning receiver tuned to Soviet AI radars and fitted to Canberra and Valiant.
  • Orange Reaper Racal "Kestrel" ESM system for Royal Navy Merlin helicopters
  • Orange Tartan – 'Auto-Astro' automated star navigation system (day) – see also Blue Sapphire (night).[12]
  • Orange Toffee – radar for Blue Envoy
  • Orange William – heavy anti-tank missile, canceled, later replaced by Swingfire
  • Orange Yeoman – Early Warning radar & guidance for Bristol Bloodhound SAGW – a.k.a. AMES Type 82


  • 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.



  • Red Achilles – flamethrower kit for the CT 25 armoured carrier
  • Red Angel – air-launched anti-ship weapon or "special bomb"[13]
  • 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[14]
  • Red Carpet – X-band radar jammer[14]
  • Red Cat – Air-launched nuclear stand-off missile cancelled 11/54.[14]
  • Red Cheeks – inertially guided bomb[14] 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 (Redeye) – 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 missile "downrated" to give Pink Hawk which became Blue Sky
  • Red Heathen – early SAM project, became Red Shoes and Red Duster[15]
  • 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 (SLAR), tested on the Victor a 40 foot long aerial under each wing. Flexing in flight corrupted the resolution. Cancelled 1962.[16]
  • Red Planet – infantry platoon anti-tank missile
  • Red Queen – rapid fire 42 mm revolver cannon anti-aircraft gun[17][18]



Non-Rainbow codesEdit

Several British military related terms have a similar "colour" format to Rainbow Codes, but are not since they do not refer to classified research projects, and some names have been used unofficially. These include:

  • Black Banana – unofficial nickname for the Blackburn Buccaneer, originally named the Blackburn ANA (Blackburn Advanced Naval Aircraft).
  • 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 gun control radar during the Falklands War. Installed in the Harrier GR.3's starboard 30mm gun pod.[22][23]
  • 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[24]
  • Green Parrot – unconfirmed low yield nuclear weapon mentioned in a 1981 New Statesman article by Duncan Campbell[25] who later claimed that it was "probably" a copy of the US B57 nuclear bomb.[26] 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.[27]

See alsoEdit


  1. ^ Jones, R (1978). Most Secret War. London: Hamish Hamilton Ltd. p. 120. ISBN 0-241-89746-7.
  2. ^ Houghton, Vince (2019). Nuking the Moon. Penguin. p. 54.
  3. ^ Guppy, Jonathan (2008). Fallout. p. 170. ISBN 9781409239734.
  4. ^ "Blue Vixen radar (United Kingdom), AIRBORNE RADAR SYSTEMS". Jane's Avionics. Retrieved 8 August 2009.
  5. ^ "Blueboar". Archived from the original on 11 April 2012. Retrieved 2012-09-15.
  6. ^ "Aviation Book Review". Aeroflight.co.uk. Retrieved 25 July 2016.
  7. ^ "Vulcan's Hammer". Crecy.co.uk. Retrieved 25 July 2016.
  8. ^ PRO. AVIA 65/1193 E10A. Tech Note GW375 p.2
  9. ^ "Greencheese". Archived from the original on 11 September 2005. Retrieved 2005-11-07.
  10. ^ Cullen, Tony & Foss, Christopher F. (1991) Jane’s Land-Based Air Defence 1990–91, Jane’s Information Group, London: ISBN 0-7106-0915-9
  11. ^ "Green Mace Anti-Aircraft Gun". Archived from the original on 4 May 2008. Retrieved 2008-04-22.
  12. ^ Crecy Publishing Ltd. "Vulcan's Hammer". Crecy.co.uk. Retrieved 25 July 2016.
  13. ^ British Secret Projects: Jet Bombers Since 1949 Tony Buttler Midland Publishing 2003
  14. ^ a b c d "Archived copy". Archived from the original on 24 October 2012. Retrieved 2012-09-28.{{cite web}}: CS1 maint: archived copy as title (link)
  15. ^ "1959 | 2460 | Flight Archive". Flightglobal.com. 25 September 1959. Retrieved 25 July 2016.
  16. ^ The Handley Page Victor, Roger R Brooks, 2007, Pen & Sword Books Limited, ISBN 978 1 84415 411 1 p.197
  17. ^ Anthony G Williams (13 May 2011). "THE RED QUEEN AND THE VIGILANTE". Quarryhs.co.uk. Retrieved 20 November 2018.
  18. ^ "Red Queen Anti-Aircraft Gun". Archived from the original on 8 October 2008. Retrieved 2008-10-30.
  19. ^ Jobson P. (2008) Royal Artillery Glossary of Terms and Abbreviations, The History Press, Stroud: 316 pp.
  20. ^ "Airborne DF has existed for over 50 years". PPRuNe – Professional Pilots Rumour Network. 22 September 2010.
  21. ^ Forster, Dave (2016). Black Box Canberras. Hinoki. pp. 210, 249. ISBN 978-1902109534.
  22. ^ "Falklands 25". Fast Air Photography.
  23. ^ Morgan, David (2012). Hostile Skies. Hachette. p. 165. ISBN 978-1780225005.
  24. ^ Green, William; Swanborough, Gordon (1976). "Royal Air Force Yearbook 1976". Books.google.co.uk. Retrieved 25 July 2016.
  25. ^ Campbell, Duncan (17 April 1981). "The Wings of the Green Parrot". New Statesman. p. 9.
  26. ^ Duncan Campbell (1986). The Unsinkable Aircraft Carrier: American Military Power in Britain. Paladin Grafton Books. p. 104.
  27. ^ Davis, R.A. (1993). "Concorde Power Plant Fire Protection System". Aircraft Engineering and Aerospace Technology. 43 (5): 26–30. doi:10.1108/eb034768.

External linksEdit