There is no real relationship between dyestuffs and glass colorants. Dyes are organic compounds; and glasses are colored with elemental mineral oxides.

It is true that most purple glass looks muddy. It must be very difficult to formulate a good purple colorant. However, it has been done. About sixteen (16) years ago I examined a fragment of a Chinese beadwork piece that was amazing, on two counts. 1) It included rich beautiful purple beads, of a tone I had never seen previously nor since then; and 2) ALL of these beads were tiny handmade wound glass beads. I was astounded.

So, it's possible to make a decent purple, and in recent years the colors of seedbeads have improved. (Every time I see new purple seedbeads, I buy thm.)

Regarding pearls, I suspect that colors (nowadays) mostly result from dying white or off-white pearls. If you cannot find a color you like, you could try to dye them yourself. I dye cords for stringing beads quite often. Or I over-dye an existing color. Without some practical experience, I could not predict the result of dying pearls. But it's worth a try—because we know it's possible.

I would hesitate to do my own dyeing. I bought some GLASS beads a couple years ago online, and they were dyed! Color came off when they got damp. Ugh!

Re: Glass hues...Years ago, I used some lovely little Czech glass beads in a line of necklaces. And a few years later, I realized they were COATED white beads, and that coating eventually peeled off. UGH again. I had to restring some of the necklaces when people brought them back. Same with certain beads made in India.

There are a LOT of Czech beads now that are coated over white, clear, or black beads. I hesitate to use them for the same reason. Maybe they're better now...??

Are your purple seed beads clear glass? You got pics?? :-)

I think you would find that, being an organic material, pearls will take a dye fairly well and easily. And once it is set the color will not rub off.

If you use Ritt or Tintext dyes, you should pull them out of the dye batch and drop them into a container of water with some vinegar in it. This will help set the dye.

Procion dyes would probably also work. You need to add salt and soda to get the reactions. Procion dyes have the reputation for being very permanent.

Grackle and sun - The fast and the fugitive : poke berry edition

it talks about cold dying by fermentation

I suggest to avoid the use of acid mordant , in this case