Had to look this up on Wikipedia - apparently they look so grey because they're covered in waxy stuff meant to prevent water loss. They're apparently purplish, inside.
Ah, cochineal red! Often hidden away in the small print of ingredients, it's a nightmare for vegetarians. Many a time I've enjoyed a strawberry milkshake only to discover to my horror that its colourant was crushed bugs. As a vegetarian, the enjoyment doesn't last long!
Obviously if you're allergic to the compound it doesn't make any difference, but it might not necessarily be made from crushed bugs --- it was synthesised in the lab 2 decades ago:
Yes, and if it could be reduced, that would be great. The meat industry is rather more barbaric though. I used to eat meat, but gave it up aged 11 after seeing how the animals are treated.
Is your intent to argue that vegetarians should consume only air? If you take just a split second to think, you can come up with the obvious vegetarian rebuttals to your statement.
I remember buying some Trader Joe's strawberry soymilk about 18 years ago and then discovering that it was nonvegetarian for this reason. Nonvegetarian soymilk isn't something you see every day (I guess unless you worked for Trader Joe's in 1999).
My wife specializes in this area with her fiberwork. I've picked up a few things.
You can also use: onion skins, avocado pits, ironwood, oak galls, copper, iron, and plenty more. It's awesome looking at some of her historic dyework books, realizing just how many reactions are going on per batch. And indigo - real indigo leaves and fermentation is just an absolute beauty to watch. The vat isn't deep blue - but turns that way when oxidized in air.
Process optimization aside, any sufficiently hungry person who would mash a snail they scraped off a rock could discover it. When exposed to air the clear liquid in the gland reacts with an enzyme also in the gland and turns purple. I haven't seen anyone mention flavor, but it is possible the dye gland is an icky part.
You can find YouTube videos of people dying cloth by just walking around, mashing snails and dribbling their juices on skeins of fibers they have wrapped around their arms.
As a former chemist, colors were always a fun part of the work. For myself, the color of copper-ammonia complex is just stunning.[1] It's incredibly deep. I used to keep a vial of it on my bench.
The spectral line of strontium is also something to behold. I was using an ICP (inductively couple plasma) torch and the color is incredibly rich.
https://en.wikipedia.org/wiki/Campari