What shadow color do you see on a nice sunny day, walking happily, listening to a music, enjoying spring landscapes, dreaming, .. Oh, I have almost lost my question!
They often appear black - it's obvious. There is no light falling on one of the sides of the object - so there is no light to reflect. But imagine, there are several light sources and they are different in their strength, and object itself is translucent.
I say here starts an art!
I used this idea in my Shadow Serie - to play with possibilities what us physics statements give. Find out what ideas may come watching on shadows - what real objects you'd found out.