Greetings, and thank you for taking the time to help me on this.
EUREKA!
I maintained the previous revisions I made to your original reply. But,
removed the system() call -- retuning it to `ls -1b`;

It appears that the only issue I had with yours originally, was the single quote marks used in the HTML
formatting -- ' vs ".
For clarity (and anyone else that might be interested):

#!/usr/bin/perl
print "Content-type: text/html\n\n";
use strict;
use diagnostics -verbose; # Desperately seeking guidance :P

use Modern::Perl;

my @l = `ls -1b`;
my $c = 0; # toggle for odd/even lines
for (@l){
    chomp;
    my $bg = $c ? "#eee" : "#ccc";
    say qq| <p style="font-family:mono;background:$bg">$_</p> |;
    $c = 0 if $c++ == 1;
}
# use strict; with use Modern::Perl; is redundant
# keeping use strict; and commenting use Modern Perl;
# would require changing "say" to "print"
[download]

Thank you VERY much. The output is beautiful! :)

#!/usr/bin/perl -Tw
use perl::always;
my $perl_version = "5.12.4";
print $perl_version;