#!/usr/bin/perl

use strict;
use warnings;
 
use HTML::TreeBuilder::XPath;
my $tree = HTML::TreeBuilder::XPath->new; # empty tree
$tree->parse_file( 'myfile.html');

my @values= $tree->findvalues( '//tr[@class=~/^violet[0-9]/]/td[1]');

foreach my $value (@values) { print $value, "\n"; }