Question

Why shadows are black in colour?

Answer 1

This happens because of Rayleigh scattering, the same property that causes the sky to appear blue. The opaque object is able to block the light of the sun, but not the ambient light of the sky which is blue as the atmosphere molecules scatter blue light more effectively. As a result, the shadow appears bluish.

Answer 2

Answer:

THIS IS BECAUSE BLACK is fundamental colour.

In shadows the wave length is Zero.

In fact SHADOWS is not fully black.

As black light has some waves length