b377 The ones which look "black" were blue but the third one along was white as it was used by West African Airways. The pic was taken with a Kodak Brownie!
I loved Strats and after the civil ones vanished I still enjoyed the various military ones which could be seen around the UK, like this one for example:
22626 Boeing C97 New York ANG Prestwick Airport 5 July 1965 :: 22626.jpg :: Fotopic.Net
A very interesting one I saw heading for London Airport in June 1959 was N404Q of Transocean Airlines.