This is a video taken in Blackfriars station on 31st October 2014. D78 stock is waiting in the westbound platform and leaves before the arrival of new S7 stock on a District line train.
This was during the transition period as the S7 stock was being introduced and the existing D78 stock was being withdrawn. During this time it was possible to get either stock on a service. The D78 stock had been introduced in 1980 originally in silver finish but they received the white, blue and red livery during their mid life refresh in 2008.
One notable feature of the D78 stock was the green colour of the handrails internally which made it easier for passengers to know they were catching a district line train, although the new D7 stock handrails are all yellow regardless of the line they are running on.
Blackfriars station is on the District and Circle lines.