It would appear that automatic recognition software is getting so good that we are nearly at the stage that converting a black & white image to a colour one can be made at the click of a mouse. There are loads of different software options around and there will probably always be one that is better than the one you are using! Most work by uploading an image to a website and then downloading the finished result. Try out a few for yourself and if you are a photographer looking for a new revenue line, perhaps this might be it.
I converted this image from about 1940 with my late mum as the little girl seated with this free app on the following website: https://www.myheritage.com/incolor but I also tried https://playback.fm/colorize-photo and https://colourise.sg.