Try to solve one problem at time challenge (impossible)

Some render spheres to test light effects on and practice my airbrush shading. Still having my reoccurring problem in rendering halftones evenly, I don't know how the pros do it, I'll try to do some in-depth digging/studying on that tomorrow. My goal with this was to try and communicate what the local color of the sphere was to the viewer using color relationships. I set out my local color first thing for the sphere and the ground plane, then just started rendering. Hopefully I made it clear enough what the local color was, I think I did a better job on this on the top sphere than the bottom. On the bright side I think I am really grasping what makes "muddy" color and how to avoid it.