Homemade colloidal silver is dark because of the silver oxide (silver rust essentially, the biproduct of the electrolysis), and if you start with rusty silver the colloid will get darker quicker than if you start with clean silver. The CS you buy from the pharmacy has this filtered out, because the idea is to drink the suspended silver (the element), not the silver oxide (a compound of silver + oxygen). I'm sure it'd still be safe to drink, but ..... erk, no thanks!
My plants don't mind the silver oxide tho ...
My plants don't mind the silver oxide tho ...