The emergence of colorized photos has been controversial amongst historians and certainly modelers. The practice has come a long way and as the technology gets more advanced even better results will prove difficult for people to tell the difference.
The latest book from Key Books embraces the colorization process and I have to say the results are pretty good. Set in the Battle of Britain starting in July 1940 through the end of October, this paperback book brings to life the black and white photos from that era. Colorization was done by Ghermán Mihály, with the help of author Clive J. M. Ellis to ensure the colors were as accurate as possible based off of current color research. This colorization really gives you a feel for the actual events. A word of caution, this technology is only as good as the artist. Different interpretations of colors are possible, but it looks like Ghermán got it correct.