sub get_distinct_colors {
  use POSIX 'ceil';

  my $n = shift;
  my $discrete = ceil($n ** (1/3));
  my @vals = map 1 - (($_-1) / $discrete), 1 .. $discrete;
  my @colors;
  my ($r, $g, $b) = (0,0,0);

  for my $i (1 .. $n) {
    push @colors, [@vals[$r,$g,$b]];
    if (++$b == $discrete) {
      if (++$g == $discrete) {
        $r = ($r + 1) % $discrete;
        $g = 0;
      }
      $b = 0;
    }
  }   

  return \@colors;
}