Green potatoes indicated the production of solanine, which is a toxin very similar to cyanide. Though it may not make an individual sick right away, concentrations of it in the system, especially for sensitive individuals, can increase inflammation and aggravate things like arthritis.
Potatoes should be fully cooked before freezing for the best outcomes. Even then, they do better if frozen as pureed/riced potatoes (preferably with a little fat added) than as diced potatoes.
Raw baby potatoes IN their skin can be frozen with some success. Also, regular smooth-skin potatoes -can- be blanched for 3-5 minutes as cubes, and frozen, and will retain their white color, however, the texture will become mealy and they won't cook properly.
Since potatoes are a relatively quick prep (30 minutes or less) from fresh, I find it better to only buy as many as I'm going to eat in a given week, store them in a neutral-temperature or slightly cool, and very dark place, and then make sure I eat them within a week or two at most. I don't buy potatoes in bulk, and have actually stopped growing my own, since even a single plant produces far more potato than just the two of us can comfortably eat that quickly.