Someone has written a bot which automatically colourises photos that are sent to it via Twitter. This is what it did with a photograph of the Darualman railway. Note that this is just for fun, and it is not intended to be historically accurate!

I colorized your image using #openfaas in 4.1 seconds #dockercon pic.twitter.com/R6AgKlyGOb

— Colorise Bot (@colorisebot) November 5, 2017