If your data is always going to be a HoHoH..., I would write a little function that plucks your attributes out for you, and saves you the tedious typing in your code. The function would accept a path to the value you're seeking in dotted-path notation. Something like this:

use strict;
use warnings;

# Recursive function to traverse a HoH according to a 
# "dotted" properties path:
sub getprop{
    my ($properties, $path) = @_;

    return $properties unless $path;

    my ($key, @remaining_path) = split /\./, $path;
    return getprop($properties->{$key}, join('.' => @remaining_path));
}

# Define our properties:
my $mylovelydata= {
       'Colour'=>'blue',
        'Entries'=> {
                'Flowers'=>  {
                           'Dahlia'=>{'Smell'=>'nice',},
                           'Rose'=>{'Colour'=>'red'},
                  }
         },
};

# Test the function
for my $flower qw/Dahlia Rose/{
    my $colour = getprop($mylovelydata, "Entries.Flowers.$flower.Colou
+r");
    $colour = getprop($mylovelydata, "Entries.Colour") unless defined(
+$colour);
    $colour = getprop($mylovelydata, "Colour") unless defined($colour)
+;

    print "A ${flower}'s color is: $colour\n";
}
__END__
A Dahlia's color is: blue
A Rose's color is: red
[download]

This allows for less typing, but more importantly, I think, it just looks a lot cleaner. You could even expand the getprop function to handle accessing arrays stashed in your properties data structure with something like Some.Array[1].Property.

Update:: This idea is actually stolen from JavaScript. It allows you to "walk" a data structure in a similar fashion. For instance, to access a hidden field named "somedata" in the second form of a web page, you'd write something like var value = document.forms[1].somedata.