Baroque pitch has A=415 whereas modern pitch is A=440. Variation like that indicate that the notion of "perfect pitch" as a measurement of something fixed is mistaken. It's more a matter of some people having a remarkably accurate musical memory.

Other people have the same kind of skill with colour, but we are more geared to the idea that colours are spread out rather than being defined at particular points, which is how we tend to think of pitch.