I prefer a data driven approach.

my @cycle = ('#fff', '#fff', '#fff', '#ccc', '#ccc');
my $i = 0;

# ...

    $foo .= $cycle[$i++ % @cycle];

# ...
[download]

That way it is a no-brainer to use any pattern you wish. "Capture similarities in code, disparities in data."

Makeshifts last the longest.