This is an unaltered photo. Is the sky really that color? No, not even in stormy weather in central Texas. How did it happen? It happened because I was taking photos indoors at B&B Quilting & Gifts and, having just learned how to change the White Balance on my camera, I had it set to Incandescent. And forgot to change it back to Cloudy when I left the shop.
I saw the dark clouds and thought they made a nice contrast background for the windmill. The blue, white, and violet contrast nicely, don’t they? A happy accident.

It really is a nice blue. And it looks different on my phone. The violet doesn’t show up on my computer. Probably my display settings don’t track with your camera settings.