Blue is the color of dreams, and the sky opens up to heaven where our wildest dreams is waiting for us. I know this is not true but I like to think that. Blue is also a very relaxing color so when we see the sky it’s very beautiful and it calm us down. I Also, it could be a reflection of the ocean sky. The real answer is complicated but of you want to know it, check out this article: WHY THE SKY IS BLUE?