This one was developed over years. I never was quite satisfied with the lighting but now I think the time has come to move on and work on something else.
Unfortunately, this really great title didn't come to me from my creativity. I've been inspired by this:
I just fooled around with the modifying option in Carrara and decided, these ones would be worth keeping.
This is a 3D scene that contains only one light. But it's enough to illuminate the spheres with different shades.