color wheel mimicking mac color select

colorwheel.tex

\documentclass[margin=5pt]{standalone}
\usepackage{luamplib}
\begin{document}
\mpfig
u := 100;
color yellow;  yellow  = (1, 1, 0);
color cyan;    cyan    = (0, 1, 1);
color magenta; magenta = (1, 0, 1);

path p, q;
p = (for i=0 upto 11: dir 30i .. endfor cycle) scaled u;
q = origin -- subpath(0, 2) of p -- cycle;

fill p
  withshadingmethod "coons"
  withcoonspatchinit (q rotated   0, white, red,     1/2[red,yellow],   yellow )
  withcoonspatchinit (q rotated  60, white, yellow,  1/2[yellow,green], green  )
  withcoonspatchinit (q rotated 120, white, green,   1/2[green,cyan],   cyan   )
  withcoonspatchinit (q rotated 180, white, cyan,    1/2[cyan,blue],    blue   )
  withcoonspatchinit (q rotated 240, white, blue,    1/2[blue,magenta], magenta)
  withcoonspatchinit (q rotated 300, white, magenta, 1/2[magenta,red],  red    )
  ;
\endmpfig
\end{document}