- use turingbot's idea for hue angle/wavelength mapping?
- saturation:
  - fit ellipses to abney data?
  - some skewed distance to white?
  - optimisation based: distort sat in hue sat map until smoother gradients?

- wire to global makefile
- put into colour module as optional inputs
- ship preset
- remove spec module
- remove openmp and use our threads
