\documentclass[border=5mm]{standalone}

\documentclass[border=5mm]{standalone}
\usepackage{luamplib}
\begin{document}
\mplibtextextlabel{enable}
\begin{mplibcode}
input colorbrewer-rgb
beginfig(1);

numeric u;

u = 42;

z0 = (0, 3u);
z1 = z0 rotated 120;
z2 = z1 rotated 120;

z3 = z0 shifted (1/2u, 3/2u * sqrt(3));
z4 = z3 shifted (-u,0);

z5-z4 = whatever * (z0-z1);
z6 = whatever [z0, z2];
y5 = y6 = y2 - sqrt(3) * 1/2 u;

z7-z3 = whatever * (z0-z1);
z7 = whatever [z1, z2];

path vii;
vii = z3--z4--z5--z6--z2--z7--cycle;

for i=0 upto 2:
fill vii rotated 120i withcolor Blues[9][i+2];
endfor
for i=0 upto 2:
draw vii rotated 120i;
endfor

endfig;
\end{mplibcode}
\end{document}