It's not an either/or. Colors (e.g. cobalt blue) and the chemical compounds (pigments) used to create them often share a name. I should have mentioned that Prussian blue isn't created *only* as a byproduct of cyanide gas -- as you point out, it was one of the earliest chemical compounds that could be reliably synthesized, and was produced long before there was enough modern chemistry to know what was in it.
Yes, it's possible that the band was named exclusively after a color -- you wouldn't raise an eyebrow at a band called "midnight blue" -- but the fact that the chemical compound Prussian blue is tied to proof of Nazi genocide, and then is used as a name by white supremacists and Holocaust deniers, is a bit too much of a coincidence for me.
You have more knowledge on the word than I.
I thought it refferred to their eye color.
When Diesbach mixed the contaminated potash with the iron sulphate, instead of the strong red he was expecting, he got one that was very pale. He then attempted to concentrate it, but instead of a darker red he was expecting, he first got a purple, then a deep blue. He'd accidentally created the first synthetic blue pigment, Prussian blue.Traditional Blues
It's hard to imagine now, given the range of stable, lightfast colours we can buy, that in the early eighteenth century artists didn't have an affordable or stable blue to use. Utramarine, which is extracted from the stone lapis lazuli, was more expensive than vermillion and even gold. (In the Middle Ages, there was only one known source of lapis lazuli, which means simply 'blue stone'. This was Badakshan, in what is now Afghanistan. Other deposits have subsequently been found in Chile and Siberia). Indigo had a tendency to turn black, was not lightfast, and had a greenish tinge. Azurite turned green when mixed with water so couldn't be used for frescoes. Smalt was difficult to work with and had a tendency to fade. And not enough was yet known about the chemical properties of copper to consistently create a blue instead of a green (it's now know that the result depends on the temperature it was made at).
The Chemistry Behind the Creation of Prussian Blue Neither Diesbach nor Dippel were able to explain what had happened, but these days we know that the alkali (the potash) reacted with the animal oil (prepared from blood), to create potassium ferrocyanide. Mixing this with the iron sulphate, created the chemical compound iron ferrocyanide, or Prussian blue.
The Popularity of Prussian Blue Diesbach made his accidental discovery some time between 1704 and 1705. In 1710 it was described as being "equal to or excelling ultramarine". Being about a tenth of the price of ultramarine, it's not wonder that by 1750 it was being widely used across Europe. By 1878 Winsor and Newton were selling Prussian blue and other paints based on it such as Antwerp blue (Prussian blue mixed with white). Famous artists who have used it include Gainsborough, Constable, Monet, Van Gogh, and Picasso (in his 'Blue Period').
The Characteristics of Prussian Blue Prussian blue is a translucent (semi-transparent) colour, but has a high tinting strength (a little has a marked effect when mixed with another colour). Originally Prussian blue had a tendency to fade or turn greyish green, particularly when mixed with white, but with modern manufacturing techniques this is no longer an issue.
Lawyers use the phrase res ipsa loquitr ("the thing speaks for itself") to describe situations like this, where the facts speak for themselves.
It's not a coincidence.
You are niggled by the connexion?