Edit: /usr/share/graphviz/gvpr/col (601B)
# test
/* color nodes using output of dijkstra */
BEG_G {
double h, hn, hf, d, sat, md = maxdist;
if (hue_near =="") hue_near = 0.8;
if (hue_far =="") hue_far = 1.2;
hn = hue_near;
hf = hue_far;
}
# test
N {
d = dist;
sat = (md - d + 1.0) /( md + 1.0);
h = hn + ((hf - hn) * d)/md;
while (h < 0.0) h = h + 1.0;
while (h > 1.0) h = h - 1.0;
color = sprintf("%lf %lf %lf",hue,sat,1.0);
/* make sure the shape is filled */
if (!match(style,"filled")>=0) {
if (style != "") style=sprintf("%s,filled",style);
else style="filled";
}
}