AK consulted a number of well known researchers to help with colour matching. Results are open to debate. The company is also a proponent of scale colour, that is, because models are smaller than the real thing, to visually match colours they must be made lighter due to the smaller surfaces.
Now, it could be assumed that whatever is in their paint bottles, that it was formulated lighter to some degree than what was actually suggested by the research, but not so. I recall reading comments from Nick Millman, who was consulted about IJN aircraft colours, and some of the AK samples he received were considered too dark - go figure. Mike Starmer who researches British Armour colours, was discouraged with AK results as none of the colours matched what he provided to them.
These are the only two researchers I've seen comment on the final products.
regards,
Jack