C:\@Work\Perl\monks
>perl -Mstrict -Mwarnings
use Data::Dumper;

use constant {
    HEIGHT => 0,
    COLOR  => 1,
    WEIGHT => 2,
    };

my %HoAoA;

while (<DATA>) {
    chomp;
    my ($key, $height, $color, $weight) = split;
    push @{ $HoAoA{$key} }, [ $height, $color, $weight ];
    }

print Dumper \%HoAoA;

print "'ef56' second color is $HoAoA{'ef56'}[1][COLOR]";

__DATA__
ef56 2.6 red 4
ef42 2.8 green 3
ef56 9.8 blue 7
^Z
$VAR1 = {
          'ef56' => [
                      [
                        '2.6',
                        'red',
                        '4'
                      ],
                      [
                        '9.8',
                        'blue',
                        '7'
                      ]
                    ],
          'ef42' => [
                      [
                        '2.8',
                        'green',
                        '3'
                      ]
                    ]
        };
'ef56' second color is blue