Question

What will be the observed colour of sky on a planet where there is no atmosphere?

Answer 1

Answer:

the colour of sky would be black

Answer 2

The black color of sky will appear in absence of atmosphere because if there would have been no atmosphere, there would be no scattering of light and hence, no scattered light is reached to our eyes and thus the sky will appear black. For example: Moon doesn't have atmosphere which the sky appears black ( As outer space ).