I think the pink does not actually sound too difficult. They have not actually paid someone to go through the harvest because pink akoya are almost universally "pinked". Also, since Mikimoto does not produce the pearls they sell, they are at the mercy of the producers and processors.
It would be interesting to see if it were possible with the natural-color Vietnamese, but the production is just so limited currently. It is a lot easier with freshwater pearls!
It would also be possible with Tahitian pearls although much more difficult!