The iconic RAF roundel underwent dramatic transformations through two world wars, from adding white rings for visibility to developing special low visibility versions for modern stealth aircraft.
The battle of Britain: 1940, Spitfire vs Bf 109E -- Battle for the bombers: Europe 1943-45, P-47 Thunderbolt vs Bf 109G/K -- Tooth and claw: duels over China, 1944, P-40 Warhawk vs Ki-43 "Oscar" -- ...