Royal Air Force roundels British air forces Royal Navy ' s Fleet Air Arm , Army ' s Army Air Corps and the Royal Air Force roundel is a circular identification mark painted on aircraft to identify them to other aircraft and ground forces . In one form or another , it has been used on British military aircraft ( including army and naval aircraft ) from 1915 to the present . Background . When the First World War started in 1914 it was the habit of ground troops to fire on all aircraft , friend or foe , which encouraged the need for some form of identification mark . At first the Union Flag was painted under the wings and on the sides of the fuselage . It soon became obvious that at a distance the St George ' s Cross of the Union Flag could be confused with the Iron Cross that was already being used to identify German aircraft . After the use of a Union Flag inside a shield was tried it was decided to follow the lead of the French who used a tricolour Cockade ( a roundel of red and white with a blue centre ) . The British reversed the colours and it became the standard marking on Royal Flying Corps aircraft from 11 December 1914 , although it was well into 1915 before the new marking was used with complete consistency . The Royal Naval Air Service meanwhile briefly used a red ring , without the blue centre , until it was sensibly decided to standardise on the RFC roundel for all British aircraft . The official order stated : In 1915 , with the roundel carried by all RFC ( and RNAS ) aircraft , the use of the Union Jack was in practice discontinued . The Royal Air Force has employed several versions of the roundel during its existence . By 1917 , a white outline was being used to make the blue of the outer circle easier to distinguish on a dark background ( at that time PC . 10 or PC . 12 camouflage doping ) . Between the wars it was dispensed with , as most RAF aircraft were now silver - doped . During the late 1930s , with the reintroduction of camouflage , the outline was reintroduced , but in chrome yellow . Use by other air arms . Aside from the RAF , the Royal Navy ' s Royal Naval Air Service ( First World War ) and later the Fleet Air Arm , as well as the air elements of the British Army also used the RAF roundels . Many nations that had been a part of the British Empire and Commonwealth continued to use RAF roundels long after achieving independence , including Canada , Australia , New Zealand , India and others until nationalism demanded unique roundels for each of those countries . South Africa replaced the red with orange ( after having experimented with completely different colours ) , Canada changed the red dot into a maple leaf ( in several different forms ) , Australia changed the red dot to a Kangaroo and New Zealand experimented with a gold , green and white fern inset in the red dot before settling on a red Kiwi . India briefly replaced the SEAC roundel ( blue on blue ) with a blue / white chakra , before adopting an orange / white / green roundel . Southern Rhodesia , the Federation of Rhodesia and Nyasaland and Rhodesia used variations on the RAF roundel featuring assegai s before adopting a green ring with a lion and tusk on a white centre in 1970 . Roundel sizes . Pre - war . Up until mid - 1938 , roundel sizes tended to vary widely , depending on the type of aircraft ; the exception to the use of type A roundels for all aircraft was seen on the overall NIVO ( dark green ) painted night bombers ( e . g . , Handley Page Heyford s ) which used type B roundels . Roundels used on aircraft painted in NIVO were duller than the normal colours . The size of the roundel was generally determined by the space available at the specified location , with a space of several inches around the edges . Some aircraft - primarily seaplanes , had a white outline around the fuselage roundel , even on silver doped finishes however this application was inconsistent so was probably not official . From 1929 , the RAF switched to a new system of colour specifications , discarding the one used since the First World War , and as a result , the colour used for insignia changed , however the changeover period appears to have extended until at least 1932 for new production , and the old colours were not overpainted , but only gradually phased out as aircraft needed to be repainted . During the Munich crisis of mid to late 1938 , most RAF aircraft adopted green and dark earth camouflage with type B roundels of reduced sizes on all upper surfaces and the fuselage sides ; though based on colour photos , these remained in the bright pre - war colours . FAA aircraft largely remained silver doped overall with type A roundels predominating . To illustrate the progression up to the end of the war the Spitfire will be used as a typical single seat - single engine fighter : Most RAF aircraft went through similar transitions , as a result of which there was little conformity , depending on when the aircraft was built and how squadrons over painted or repainted the roundels . Second World War . By the beginning of the Second World War on 3 September 1939 , RAF roundel sizes started to show more conformity . On 30 October , all commands were ordered to change upper wing surface Type B roundels to Type A . Further instructions ordered all but fighters and night bombers to have Type A under the wing tips . This was clarified in November to the effect that only reconnaissance maritime aircraft ( e . g . , Short Sunderland flying boats ) would have the Type A on the upper wings but all aircraft would use the Type B on the sides . A decision was made to make roundels more conspicuous and , in May 1940 , the yellow outer ring was ordered to be added back to fuselage sides ( along with red , white , and blue stripes on the fin ) . Where possible , the yellow should be the same width as the blue , but on Spitfires with their narrower fuselages a thinner ring was acceptable . Also in May , an order was made to put red , white , and blue roundels on the underwings of all fighters , with an addendum that where the roundel was on a black background it should be outlined in yellow . In June , orders were given for the half black / half - white underwing scheme to be replaced by " sky " Underwing roundels were dispensed with until August when they were ordered back . It should always be borne in mind that because of the pressures of front - line service there were always exceptions to the standards set by the RAF and that deadlines were not necessarily met . Although type C and C1 roundels were meant to be in use by July 1942 some Spitfires displayed type A and A1 roundels as late as October : Although the Spitfire is used as one example , because it was one of the few British aircraft to see front - line service before , during and after the Second World War , other aircraft types went through similar transitions . During the transition from A type to C type roundels some Hawker Typhoon s displayed 42 - inch type C1 roundels which were simply modified type A1s . After June 1940 the official sizes for roundels were : Many variations could be seen because of the problems involved in interpreting instructions or repainting aircraft in front - line service , but most production aircraft conformed to these basic dimensions . SEAC and RAAF . In the China / Burma / India ( CBI ) theatre and Pacific it was decided in about May 1942 that the red centre spots on RAF roundels could be confused with the red " hinomaru " carried by Japanese aircraft . The inner red circle was removed after a RAAF No . 11 Squadron Catalina was mistaken for a Japanese aircraft by a US Navy Wildcat in the Pacific Theatre and attacked . As a result roundels were mostly modified in the field by painting over the red with white . Often the yellow outer rings of type A1 roundels were left intact . No British or American built aircraft had factory painted SEAC style roundels ; all aircraft had to be repainted , and , in many cases re - camouflaged by Maintenance Units behind the lines or by front line squadrons . Spitfires were first used by the Royal Australian Air Force over Northern Australia in October 1943 . The Mk VCs had their 36 in type C1 fuselage roundels modified to 32 in SEAC types by painting out the yellow outer ring in the camouflage colours and over - painting the red centre in white . The lower wing type C roundels and upper wing type Bs were also modified by over - painting the red centres in white . The red fin stripe was also painted out with white and , in many cases the blue was extended forward 1 in making equal widths of 12 in . RAAF Mk VIIIs had their roundels and fin flashes modified in the same ways , although some had their 55 in upper wing roundels overpainted and replaced with 32 in SEAC roundels . Fin flash . All Royal Air Force aircraft carry a flash on the fin . This is either red / white / blue , or red / blue on camouflaged aircraft , with the red stripe nearest the leading edge . The Royal Navy and Army do not use the fin flash but have the words " ROYAL NAVY " or " ARMY " on the rear fuselage or fin instead . A current exception to this are the Harrier GR7s and GR9s of the Naval Strike Wing , which carry similar markings to RAF Harriers . The fin flash can be rectangular , slanted or tapered , depending on aircraft type . In a situation similar to that of the roundels , the fin flash is also shared with the air forces of Australia and New Zealand . The fin flash evolved from the rudder stripes painted on the rudders of early RFC and RAF aircraft during the First World War , the markings comprising blue , white and red vertical stripes doped on the rudder . However , with the performance of aircraft increasing considerably during the 1930s , the practice of applying painted markings onto the ( then manually powered ) control surface s was discontinued because of the need to rebalance the controls - failure to do this could have adverse effects on the surface ' s aerodynamic balance , possibly leading to flutter of the control surface at high airspeeds . It was for this same reason that the positioning of the wing roundels was revised so that they no longer overlapped the ailerons . In an attempt to conform to the appearance of French military aircraft , rudder stripes reappeared on aircraft ( mainly Fairey Battle s and Hawker Hurricane s ) of the RAF based in France , starting in early September 1939 . These stripes were painted in standard RAF colours in the order blue , white , red . Fin flashes were officially adopted in June 1940 . For the first six months there was no conformity in the width or height of the stripes and they were painted to cover as much of the fin area as possible . With one or two exceptions the order was red ( leading edge ) , white , blue . In December 1940 type A fin flashes were standardised : height was 27 inches , width 24 inches , divided into three red , white and blue stripes ( e . g . : photo six , the Sea Hurricanes show this standardised fin flash ) . On some aircraft , e . g . ; photo reconnaissance Spitfires the fin flash was about half these dimensions . In July 1942 , with the adoption of the type C and C1 roundels the fin flash became 24 in square for RAF fighters , the stripe widths becoming 11 in red , 2 in white and 11 in blue . There were some exceptions ; RAF Mustangs all used fin flashes which were 27 in high by 24 in wide . In early 1944 some aircraft types were painted in a " High - altitude " camouflage scheme and adopted type B roundels and fin flashes . The then - current RAF fin flashes were also adopted for USAAF aircraft operating alongside British and Commonwealth forces in the Mediterranean theatre in 1942 , appearing on US Curtiss P - 40 fighters and B - 25 Mitchell bombers . Colours . Roundel and fin - flash colours changed several times during the First World War because of severe problems with fading . The third standard ( VB3 and VR3 ) would be used until the early 30 ' s when much brighter colours replaced the red and blue at the same time that rudder stripes were omitted . The red and blue were both duller and less saturated than later versions and varied considerably as paint was usually mixed locally . The actual switchover began in 1929 but new aircraft were still being delivered in 1932 with the earlier colours . For the period from the early 30 ' s until 1938 , Roundel Red was close to FS 595 21136 and the Roundel Blue was slightly lighter and brighter than FS 595 15056 . Trainer Yellow was close to FS 595 23538 . Photo 2 , a restored Bristol F . 2 Fighter is a fairly good representation of the late interwar colours . On fabric covered aircraft these were glossy ( as was the general finish ) until dulled with age , even during the First World War . In 1938 , with the threat of war looming , new markings colours were introduced along with camouflage . The Blue was darker , becoming similar to FS 595 25050 while the Red became a slightly brownish brick - red , about FS 595 20109 . The Trainer Yellow stayed the same shade but all colours were now matt . These colours remained standard for another eight years . To further complicate matters , old stocks continued to be used up - a series of colour photos of a Miles Master show wing and fuselage roundels ( C & C1 ) in dull colours , while the fin flash remains in the bright pre - war colours , albeit with the later proportions . Other colour photos show a mixture of bright and dull colours being used on the same insignia - though all instances found have been of trainers . Post war colours were specified by the new BS 381 colour standard and approximate the late pre - war colours except for special cases , such as anti - flash markings and the current low visibility markings .