Like this?

#!/usr/bin/perl -w
use strict;
use CGI;

my $q = new CGI;

my @colors = qw(red yellow pink green orange purple blue);

my @chosen = qw(red green purple);

print $q->header,
      $q->start_html,
      $q->start_form,
      $q->scrolling_list(-name     => 'color',
                         -values   => \@colors,
                         -default  => \@chosen,
                         -size     => 5,
                         -multiple => 'true'
      ),
      $q->submit,
      $q->end_form,
      $q->end_html;

exit(0);
[download]

cLive ;-)