use autodie;
use File::Temp qw(tempfile);
my @RULES = (
             { dir  => '/path/to/dir1',
               mods => [ 'yellow', 'green' ], [ 'red', 'blue' ] ],
             },
             { dir  => '/path/to/dir2',
               mods => [ [ 'puce', 'chartreuse' ], [ 'lime green', 'magenta' ] ],
             },
             );
...
for my $rule ( @RULES ) {
    chdir $rule->{dir};
    for my $file ( glob( .* * ) ) {
       open my $input, '<', $file; 
       my ($output, $outfile) = tempfile(); 
       while ( my $line = <$input> ) {
           chomp $line;
           for my $sub ( @{ $rule->{mods} } ) {
               $line =~ s/$sub->[0]/$sub->[1]/
           }
           print $output $line;
       }
       close $input;
       close $output;
       replace_file( $file, $outfile );
    }
}