This is the setup for all the future images in the gallery of circle images.

There is a blue sphere at coordinates (0,0,700) with radius 300. Behind it is a larger green sphere, with center (-30,-30,900) and radius 400.

There isn't much special about this picture - the spheres are neither reflective, nor are there light sources. It's just ambient brightness that lets us see them. This is simply a reference image for the weirdness that's about to happen.