Okay, it looks like colour 3 is approximately phase offset 0, and the palette wraps around after 14 entries, not 16. Also got a bit less dependent on floating point accuracy for the step.
Okay, it looks like colour 3 is approximately phase offset 0, and the palette wraps around after 14 entries, not 16. Also got a bit less dependent on floating point accuracy for the step.

TomHarte/CLK,TomHarte/CLK,TomHarte/CLK,TomHarte/CLK,TomHarte/CLK