Wherever I search I cannot filter out WWII noise. After the end of the war, the RAF and RN changed their cockpit colours. The RN went black fairly quickly, though I am not sure exactly when, or how long it lasted. But what did the RAF do, and exactly when did they order manufacturers to change?
I'm not sure of the exact year, but it was very late fifties. The Gnat trainer and Lighting had grey cockpits and all the other early jets had black. The earliest fighter Gnats had a black cockpit so that dates it quite well, around '58
Late Spitfires had black cockpits - there were produced on the same production lines as Seafires which had to be black so it made it easier. All HSA group aircraft had black cockpits from late 42-early 43 onwards.