It's possible that even when the boxes were new, the box art would come out a little less saturated than real life because you have to take a photograph with a

It's possible that even when the boxes were new, the box art would come out a little less saturated than real life because you have to take a photograph with a very long exposure to avoid getting a big scan stripe. I say "a very long exposure", but it's still small fractions of a second - not astrophotography, but maybe 1/10th. Still, with that you'd need to stop down a lot to get saturated colours, and given the mood of the day it's likely they were happy to get something usable and "okay it's fine, ship it".