RE: ...it is probably tetrasilver teroxide or AG4O4

I hate to say this, but... I think you're being taken for a ride.

That said, what about feeling better? ie, You seem to have based your review on herx reactions, though you haven't mentioned your overall wellness factor following intake. Along these same lines, would be willing to share such information as intake methods, durations, quantities and solution types(variants, ppm etc)?

As for colouration and chemical compositions, I'd add that nanoparticle silver solutions like Mesosilver are pure elemental silver and distilled(or purified water). And nothing else. Which is an amber or tea colour by default as a result of particle size/density. However, if/when solutions such as mesosilver are exposed to the air or elements they can change colour due to oxidation. Which would likely results in silver oxides.

That said, the makers of Mesosilver "Purest Colloids" go-on to state that this colour change doesn't actually affect the performance of their particle silver solution. Though I have hard time accepting this given the inherent differences between pure elemental silver and silver oxides based on user feedback and independent lab tests.

As for the dark colour, I'm afraid this may not necessarily be due to the initial colour of the compound with none soluble colloidal solutions. ie, a high quality, very small but dense colloidal solution(20ppm) will exhibit a crystal clear gold colour, whereas the same solution will change colours as the particles grow in size. This leads into an orange or tea coloured solution toward a brown, and eventually, a grey to black.
That said, there are several other factors which could affect colouration by chemical composition(particle) such as additives. Which would then contribute to further colour shifts within the spectrum(see: plasmon resonance). ie, green to blue

Hope this helps