This is a variation on the Radial Interleaving of Lightness and Saturation experiment.
An HSL format (with hue, saturation and lightness dimensions) is adopted for the colour space and a polar coordinate system is adopted for the pixels.
Hue is then matched to angles and both lightness and saturation are matched to distances from the centre of the image.
In this variant lightness and saturation are made to change along the radials using a pattern that helps softening their transitions.
The pattern turns out to reflect the Thue-Morse sequence.
Image licence: Public Domain (CC0).
