Hi, and welcome-- you came to the right place for answers.
1. Without having seen your pearls, I will tell you that what is inserted into these akoya saltwater oysters is real freshwater cultured pearls (not akoya cultured pearls, which are significantly more costly.)
Freshwater pearls come in natural colors of white, cream, pink, peach, lavender. I would like to see an in-focus photo of the eggplant purple pearl before commenting on that one. There are some naturally purple pearls but most are more lavender than purple unless dyed. Some of these companies sell dyed freshwater pearls; black is common, and I've seen some green ones that are dyed. I'm sure they sell other dyed colors too.
2. The oysters are not returned to the water after having had a freshwater pearl put in. They are put into a pickling chemical that makes them close up tight. The oysters are killed; they do not die a natural death, either, as some claim.
3. In my opinion it is a waste of money since one can buy freshwater pearls at a better price without going through these parties.
4. Maybe it was fun before you knew all this, but now that you know, how can it be fun to buy a canned dead oyster in chemicals with a freshwater pearl inside, knowing that the sale is based on a deception?