The wonderful video below was shot in London in the mid-1920s by Claude Friese-Greene, a British pioneer of colorized cinematography. His method of colorizing film, called Friese-Greene Natural Colour--done during the age of silent movies--never caught on, and eventually was eclipsed by the Kenemacolor technique, also developed in Britain, and then by the Technicolor technique, developed in America.
If you're a fan of Downton Abbey (and who isn't?), the video is of special significance. Downton's beginning episodes took place in 1916; when the show's third series airs this winter, the episodes will take place in the early 1920s, right before this footage was shot. How delightful to have such insight into the time period of our beloved Downton!
VIDEO: London in 1927 (Note: British Film Institute has corrected the date to 1926)