Gradient Mosaic Technique

Use super slicer, set the bottom and top infill patterns to Concentric (filled). 
Use coextrusion filament.
Set the number of external perimeters for the bottom layer to 0 with a height range modifier.

if you make an interesting pattern of shapes just on the bottom layer you can get a cool effect where there are gradients between the shapes.

Regular concentric infill has ADHD and does its paths in a random order in random directions clockwise vs counter clockwise and does not look nearly as good. 

Moiré patterns are making my photos of this effect look worse then it is.