Model based on color profiles above, both painted in White-Black underside with RAF medium brown and forest green camouflage in upper surface. RAF evolved through a series of national insignia designs for top - bottom - side - tail fin aircraft sections during WW2. Note large RAF Type-A roundel with yellow band for underside insignia, this yellow band subsequently left out as war progressed. General rule in 1940 was to paint underside insignia for aircrafts operating in European mainland, planes flying within British Isles had no underside insignia.

Spitfire KL-N (serial number N3173 not painted) flown by Commonwealth Pilot Officer Colin Gray from New Zealand. He scored his first victory against German Bf-109 fighter over Dunkirk on 24 May 1940. By war's end, Gray was New Zealand's top ace with 27 kills. Spitfire KL-B (nicknamed KIWI, serial number N3183 not painted) was flown by New Zealander Pilot Officer Alan Deere, credited with 7 victories over a 5-day span defending Dunkirk beachheads. Plane KL-B was destroyed during Battle of Britain on 9 July 1940, its pilot A. Evershed was killed in action. FYI, Kiwi is a species of birds in New Zealand, hence its caricature used by New Zealand pilots and was officially adopted as its air force insignia by 1960s. Royal New Zealand Air Force - http://en.wikipedia.org/wiki/New_Zealand_Air_Force

Commonwealth is a socio-economic-political alliance of British colonies with United Kingdom with origins dating back to 15-century. In WW2, Commonwealth nations (ex. Australia, New Zealand, Canada, South Africa) sent volunteers, resources, personnel to fight along side with the British throughout Europe and Asia theaters. Commonwealth - en.wikipedia.org/wiki/Commonwealth

Rollover : In 1940, RAF utilized two basic camouflage patterns for upper surfaces, Scheme A and Scheme B, both are identical expect for its placement on either port or starboard wing. Underside was the "White and Night" pattern, its sharp contrasting color enabled rapid aerial identification to prevent Friendly-Fire incidents. This pattern was also used by German night-fighters operating over European mainland in late war years. Friendly fire - en.wikipedia.org/wiki/Friendly_fire