Bob I expect this is the picture that you are referring to? It's an ATS girl training on an impressed Royal Enfield 250 Model D. The picture has been bandied around for years, erroneously declaring to be "Her Madge".
In fact the picture appeared in "The Motorcycle" in 1942 when she was just 15 years old. She didn't attend ATS training until she was 18 and I think it was actually 1945.
The colour picture is from a small series with the Tilly and K2 ambulance. I don't know if it was colour film or tinted?? Ron