Question

Why is the sky not blue as seen from space?

Answer 1

Because there is no reflection in space

Answer 2

The daytime sky is indeed blue as seen from space. Look closely at any color-accurate photograph of earth taken from space and the blue tint of everything on the day side is unmistakable. This blue tint is the sky. The daytime sky as viewed from space is not a solid, uniform blob of blue for two reasons: (1) there are white clouds in the sky which can be seen just as well from space as from earth's surface, and (2) the sky is not opaque.