Thanks for all the replies everybody, tho I haven't had a chance to read them yet, but my post has obviously struck a chord, given the no of responses. Anyway, here are the links to my three other photos of Argosies. Firstly, a civil example, G-APRL, in the colours of its last owner, Elan. This aircraft is preserved at the Midlands Air Museum immediately adjacent to Coventry airport:
JetPhotos.Net Photo » G-APRL (CN: 6652) Private Armstrong Whitworth 650 Argosy by Michael Blank
Then another civil aircraft, sister ship to G-APRL, G-APRN, photographed thirty-seven years ago, in March 1974, at Castle Donington, in ABC colours:
ABC Argosy at Castle Donington 16-3-74 | Flickr - Photo Sharing!
And finally, another RAF aircraft, XP411/8442M, preserved at Cosford:
ScanImage16 1024 | Flickr - Photo Sharing!
The first RAF machine is obviously in ASC colours, but can anyone tell me please what are the rather handsome colours carried by the Cosford example?