I counted 126 possible combinations using Math::Combinatorics.

#!/usr/bin/perl

use strict;
use warnings;
use Math::Combinatorics;

my @arrays = ( qw[ red blue ],
               qw[ small medium large ],
               qw[ 1 2 3 4 ],
);

print "combinations of 4 from: ".join(" ",@arrays)."\n";
print "-----------------------------".("--" x scalar(@arrays))."\n";
print join("\n", map { join " ", @$_ } combine(4,@arrays))."\n";
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