From what I researched last night, there are supposedly over 300 cases of argyria that have been reported and these numbers were from an article I read from 2001.
This is relatively new, since colloidal silver was replaced by antibiotics in the 40's. Some Doctors continued its use up to the mid 50's, until the product was removed by the FDA due to argyria.
Read about a Senate candidate that turned blue due to use of colloidal silver, at :
https://archives.cnn.com/2002/ALLPOLI...ate/index.html
pictures can be viewed at:
https://www.motherjones.com/images/stan_jones
https://www.motherjones.com/news/update/2006/1
Montana's Libertarian candidate for senate has turned blue from drinking a silver solution that he believed would protect him from disease. He started making his own in 1999 and by 2002 was the permanent color blue/gray. Article tells how he made his solution with heating silver wires in a cup.
He was going to try to reverse this, and it would be interesting to see what he used to try, and if he had any success. Anyone finds out more, post it here for us. Thanks.