He turned blue for 2 reasons:
1: He used massive doses, and
2: He did not use pure distilled water. Silver readly bonds with other molecules, specifically chlorine in this case. When chlorine is present it makes silver chloride either in the final product or even within your body if it can find chlorine in your body. This is what migrates to your skin and turns it blue.
Thus, when I make Colloidal Silver I am careful not to use tap water or allow anything into the mix that can corrupt the final product.
There are millions of folks who use silver medicinally that have not and will never turn blue.