Dave Green's 'cubehelix' colour scheme.
See cubehelix homepage at:
https://www.mrao.cam.ac.uk/~dag/CUBEHELIX/
Calculation from:
http://astron-soc.in/bulletin/11June/289392011.pdf

Examples

use cube_helix::CubeHelix;
// Get default values
let ch: CubeHelix = Default::default();
// Returns color white: (255,255,255)
let colors = ch.get_color(1.0);