gistfile1.txt

#!/usr/bin/perl
use strict;
use warnings FATAL => 'all';
use vars qw($VERSION);

use Term::ExtendedColor::Xresources qw(get_xterm_color set_xterm_color);

my $colors = get_xterm_color(
  {
    index => [0..255],
    type  => 'hex',
  },
);

for my $c(sort { $a <=> $b  } keys %{ $colors }) {
  #print "\e[48;5;${c}m \e[m";

  my $hex = sprintf("%6x", eval "0x$colors->{$c}->{rgb} + $c");
  set_xterm_color(
    {
      $c => $hex,
    },
  );
}