Two-strip technicolor footage of London from 1927, courtesy of a friend who sent me this link today from The British Film Institute. Despite the rather corny intertitles between shots, this to me is remarkable footage.
The earliest technicolor feature films I know of came out of Hollywood around 1922, and were few and far between. The most famous pre-sound color film was Douglas Fairbanks' "The Black Pirate" from 1925.
In America, Technicolor company that created similar technology only possible to shoot short films like this as novelty items. The British company that shot this footage was using very expensive equipment for its time. (Credit is given here to Claude Friese-Greene for the photography--I would guess he was the son of early cinema pioneer William Friese Greene whose attempts to be creditted for the invention of moving picture stock was the subject of the excellent 1951 film "The Magic Box" with Robert Donat.) Whether Mr. Friese Greene was working with the American Technicolor Company, which patented its two-strip process in 1922, is something I'm not certain of as yet.
Since it was only a two strip process--mostly highlighting reds and blues--the green colors are often muddy. Better results had to wait for the three strip color Technicolor process from 1933 on. Because of The Great Depression, color films remained limited in number for many more years to come.