First, there are no reports in the medical literature of anyone ever turning blue or otherwise harmed by drinking real colloidal silver. There are reports of people turning blue from drinking ionic silver made or sold as colloidal silver.
Its true that silver nanoparticles give off silver ions BUT, they only do that when they contact a pathogen, because of the difference in the electric charge of the pathogen. Silver nanoparticles do not just blow off ions, otherwise the particles would decrease in size over time, and the color would shift toward green. This does not happen even with samples stored for many years.
As for particles being too small, that's not likely. The particles always tend to grow, unless stabilized. The stabilizer stops particle growth at a size mostly determined by the stabilizer (Karo, maltodextrin, cinnamon, polyvinylpyrolidone, gelatin, etc).
When a silver ion enters a healthy cell, it reacts with and binds to sulfur or selenium, and becomes permanently stuck there, The reaction is not reversible and so argyria is not reversible.
I had a dog that was getting constant skin infections when she was 13. For the next 2 years, I gave her nothing to drink except 20ppm Colloidal Silver and when she died, her skin was still pink with no trace of argyria.