#!/bin/perl5

use strict;
use warnings;

my @search = ("red", "orange", "blue");
my @replace = ("yellow", "black", "green");
my %replacements;
@replacements{ @search } = @replace; 

my $string = q(red orange blue blue);

for my $key (keys %replacements){
  $string =~ s/$key/$replacements{$key}/ge;
}