I found a neat photograph [0] of the process of extracting Tyrian purple from Murex snails. There's a remarkable variety of blue pigments that separate out of that, alongside of the famous purple.
(Murex snails being a different hypothesis for the source of the forgotten tekheret dye, separate from the cuttlefish one).
(Murex snails being a different hypothesis for the source of the forgotten tekheret dye, separate from the cuttlefish one).
[0] https://static01.nyt.com/images/2024/03/05/multimedia/05SCI-...
photo from https://www.nytimes.com/2024/03/05/science/archaeology-tyria... ("In Israel, a 3,000-Year-Old Purple Factory")