I believe Pina's book on Archimede Seguso caused much confusion. She calls the polveri glass in the book sfummato. Sfumato means smoke. The technique was probably developed by Alfredo Barbini when he was at VAMSA in the 1930s. The glass is exposed to smoke to give the mysterious grey effect. It is the same effect that other companies have tried to achieve since then.
In painting, sfumato refers to shading colors together so there are no distinct borders. Using that description, we could say that the polveri things fit. But it causes much confusion. I would have stuck to calling them polveri, because what we think of as sfumato in Murano is a totally different technique.
I don't know what Archimede called his polveri technique. It would be interesting to find out. The blending of colors with gold is indeed pretty. I posted two pictures below. The first is a Barbini sfumato bird. The second is an Archimede Seguso polveri bird. The Seguso bird is courtesy of Mike Stevens. (My own polveri birds were all brown, which would have been confusing indeed.)