hmm,

@search = ("red", "orange", "blue");
@replace = ("yellow", "black", "green"); 
$text = "my pig is red, my orange is orange and the sky is blue"; 
foreach (0..$#search) { 
    $text =~ s/$search[$_]/$replace[$_]/;
} 
print $text,"\n"
__END__
my pig is yellow, my black is orange and the sky is green
[download]

To replace every ocasion in text, use the g-modifier (s///g)

not a beauty, but works...