Living in Arizona, I have been able to grow my peppers all year round with only a small negligible effect in the winter months. On curious thing occurs though. Many of the peppers go from green to black during the cold months but it never happens the rest of the year. The fruits aren't completely black, maybe just a side, or the bottom. The fruits are not bad either, not like it was frosted and the cells are dying (and not mushy). They are as healthy as ever, just black. It seems that it usually happens on the top side of the pepper, the side that receives the sun and I don't believe that I see it on the bottom where the "sun doesn't shine". Every once-in-a-while, I'll see the same thing in the stores. None of the red ones get black either, just the immature green. There is no noticeable taste difference either. Can anyone explain what is happening?