use warnings;
use strict;
use XML::LibXML;

my $doc = XML::LibXML->load_xml(IO=>*DATA);
for my $product ($doc->findnodes('//product')) {
	my $item = $product->findvalue('./item_number');
	my @colors = map {$_->textContent}
		$product->findnodes('.//color_swatch');
	print "ITEM NUMBER: $item COLORS: @colors\n";
}

__DATA__
<product description="watches" product_image="watches.jpg">
	<item_number>QWZ5671</item_number>
	<size>
		<color_swatch image="red_watches.jpg">Red</color_swatch>
		<color_swatch image="burgundy_watches.jpg">Burgundy</color_swatch>
	</size>
</product>