#! perl -slw
use strict;
use Data::Dumper;

my $data = do{ local $/; <DATA> };

my %hash = eval "$1"
	if $data =~ m[
		\n%some_hash\s*=\s*
		(
		\( .* \);
		)
	]sx;

print Dumper \%hash;

my %newHash;
for my $state (keys %hash ) {
	push @{ $newHash{ $_ } }, $state
		for split /\s*,\s*/, $hash{ $state }{colors};
}

print Dumper \%newHash;

__DATA__
Various other perl statements before the hash definition
Various other perl statements before the hash definition
Various other perl statements before the hash definition
Various other perl statements before the hash definition
Various other perl statements before the hash definition
Various other perl statements before the hash definition

%some_hash =
  (
    'NEW_YORK' =>
    { 'capital' => 'Albany',
      'colors' => 'black, green, blue',
      'bird' => 'pigeon'
    },
    'MASSACHUSETTS' =>
    { 'capital' => 'Springfield',
      'colors' => 'red, white, blue',
      'bird' => 'turkey'
    }
  # etc
  );

Various other perl statements after the hash definition
Various other perl statements after the hash definition
Various other perl statements after the hash definition
Various other perl statements after the hash definition
Various other perl statements after the hash definition
Various other perl statements after the hash definition
Various other perl statements after the hash definition

##</code><code>##

P:\test>277327
$VAR1 = {
          'MASSACHUSETTS' => {
                               'bird' => 'turkey',
                               'colors' => 'red, white, blue',
                               'capital' => 'Springfield'
                             },
          'NEW_YORK' => {
                          'bird' => 'pigeon',
                          'colors' => 'black, green, blue',
                          'capital' => 'Albany'
                        }
        };

$VAR1 = {
          'green' => [
                       'NEW_YORK'
                     ],
          'white' => [
                       'MASSACHUSETTS'
                     ],
          'black' => [
                       'NEW_YORK'
                     ],
          'blue' => [
                      'MASSACHUSETTS',
                      'NEW_YORK'
                    ],
          'red' => [
                     'MASSACHUSETTS'
                   ]
        };