red -> yellow -> green -> cyan -> blue -> magenta -> greyscale(white -> black)

##</code><code>##

#!/usr/bin/env perl

use strict;
use warnings;

use List::Util 'uniq';

my @input;
{
    no warnings 'qw';
    push @input, [qw{
        #000000 #0000ff #ff0000 #ffffff
        #00ff00 #ffff00 #00ffff #ff00ff
        #000000 #00007f #7f0000 #7f7f7f
        #007f00 #7f7f00 #007f7f #7f007f
    }],
    [qw{
        #000000 #716373 #704A2B #AF7E45 #963049 #AA2261
        #B24551 #E6212E #FF0000 #001200 #FFDE72 #F55B73
    }];
}

for my $i (0 .. $#input) {
    my %data;
    $data{$_} = [ map hex, /(..)(..)(..)$/ ] for uniq @{$input[$i]};

    my @ordered;

    for my $prime (qw{R G B}) {
        for my $type (qw{rgb ycm}) {
            push @ordered, sort_colours(\%data, $type, $prime);
        }
    }

    push @ordered, sort_colours(\%data, qw{grey R});

    print_table(\@ordered);
}

sub sort_colours {
    my ($data, $type, $prime) = @_;
    my @result;
    my @hier = $prime eq 'R' ? (0,1,2)
             : $prime eq 'G' ? (1,2,0)
             :                 (2,0,1);

    push @result, sort {
        $data->{$b}[$hier[0]] <=> $data->{$a}[$hier[0]]
        ||
        $data->{$b}[$hier[1]] <=> $data->{$a}[$hier[1]]
        ||
        $data->{$b}[$hier[2]] <=> $data->{$a}[$hier[2]]
    }
    grep {
        if ($type eq 'rgb') {
            $data->{$_}[$hier[1]] < $data->{$_}[$hier[0]]
            &&
            $data->{$_}[$hier[0]] > $data->{$_}[$hier[2]]
        }
        elsif ($type eq 'ycm') {
            $data->{$_}[$hier[0]] == $data->{$_}[$hier[1]]
            &&
            $data->{$_}[$hier[0]] > $data->{$_}[$hier[2]]
        }
        else {
            $data->{$_}[$hier[0]] == $data->{$_}[$hier[1]]
            &&
            $data->{$_}[$hier[0]] == $data->{$_}[$hier[2]]
        }
    } keys %$data;

    return @result;
}

sub print_table {
    my ($colours) = @_;

    print qq{<table border="1">\n};

    for (@$colours) {
        print qq{  <tr><th><tt>$_</tt></th><td bgcolor="$_" width="100">&nbsp;</td></tr>\n};
    }

    print "</table>\n";

    return;
}