use strict;
use warnings;

# Use this to show the data structure.
#
use Data::Dumper;

# Initialise a hash reference and a sequence no.
#
my $rhPreserve = {};
my $insertionOrder = 0;

# Read our data line by line, chomping off the newline
# and splitting on the ":" and using the colour name
# as the key and RGB for the value.
#
while(<DATA>)
{
    chomp;
    my ($value, $key) = split /:/;

    # Make an entry in the hash reference for this colour but
    # the value is another hash with two key/value pairs, one
    # for our RGB value and the other the insertion order
    # which we increment after insertion.
    #
    $rhPreserve->{$key} =
    {
       value => $value,
       insertionOrder => $insertionOrder ++
    };
}

# Use Data::Dumper to print out the hash reference so we can see
# what we have constructed. The colour "keys" will come out in an
# order determined by the underlying hashing algorith.
#
my $dd = Data::Dumper->new([$rhPreserve], ["rhPreserve"]);
print "Data structure\n", $dd->Dumpxs();

# To use our insertion order, which we have preserved in the hash
# reference, we can sort by "insertionOrder" then use the sorted keys
# to access the hash reference.
#
my @keysInInsertionOrder =
   sort
   {
      $rhPreserve->{$a}->{insertionOrder}
      <=>
      $rhPreserve->{$b}->{insertionOrder}
   }
   keys %$rhPreserve;
print "Data in insertion order\n";
foreach (@keysInInsertionOrder)
{
    print
       "Insertion order - $rhPreserve->{$_}->{insertionOrder}\n",
       "     Key - $_\n",
       "     Value - $rhPreserve->{$_}->{value}\n";
}

__END__
255 250 250:snow
248 248 255:GhostWhite
245 245 245:WhiteSmoke
220 220 220:gainsboro
255 250 240:FloralWhite
253 245 230:OldLace
250 240 230:linen
250 235 215:AntiqueWhite
255 239 213:PapayaWhip
255 235 205:BlanchedAlmond
255 228 196:bisque
255 218 185:PeachPuff
255 222 173:NavajoWhite
255 228 181:moccasin
255 248 220:cornsilk
255 255 240:ivory
255 250 205:LemonChiffon
255 245 238:seashell
240 255 240:honeydew