If I had to guess (and that is all this is is a guess) I would say that in the solutions containing water wetter and purple ice that the aluminum is forming an aluminum hydroxide coating due to the high pH of those additives. This coating I suppose you could call corrosion, but in actuality it is a good thing because it will prevent any long term dissolution of hte aluminum and enhance its resistance to redox reactions with copper (galvanic corrosion). I know water wetter states that it is alkaline; not sure about purple ice. I am a chemist of sorts (environmental chemist), but I would have to know a bit more about the makeup of the organics used in these products to make a really educated guess. My gut instinct is that the red coloring is actually just that; the active ingredients are surfactant and base and both of thsoe are colorless. People have a hard time paying $7 for what looks like bottled water though. Make it red or purple and it seems more reasonably priced.
