You can build a regex with the @search array, and substitute in the @replace value via a hash lookup.

my $s = "I have red stuff, blue stuff, orange stuff, and more red stuf
+f.";
my @search = ("red", "orange", "blue");
my @replace = ("yellow", "black", "green");
my %replacements;
@replacements{ @search } = @replace;    # use a hash slice to populate
+ the search=>replace pairs.
my $re = join '|', @search;
$s =~ s/\b($re)\b/$replacements{$1}/g;
print $s;
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