Try

#!/usr/bin/perl -w
use strict;
use Win32::OLE;
use Win32::OLE::Const;

my $wd = Win32::OLE::Const->Load("Microsoft Word 14.0 Object Library")
+;
printf "wdRed = %s\n",   $wd->{wdRed};
printf "wdGreen = %s\n", $wd->{wdGreen};

my $document_name = 'C:\Users\boss\worddoc.doc';
my $word = Win32::OLE->GetActiveObject('Word.Application')
    || Win32::OLE->new('Word.Application','Quit')
    or die Win32::OLE->LastError();
my $document = $word->Documents->Open($document_name)
    or die Win32::OLE->LastError();
my $paragraphs = $document->Paragraphs();
my $n_paragraphs = $paragraphs->Count();
for my $p (1..$n_paragraphs) {
    my $paragraph = $paragraphs->Item($p);
    my $text = $paragraph->Range->Text();
    my $font = $paragraph->Range->Font();
    if ($text =~ /interviewer/i) {
      print "$text\n\n";
      $font->{'ColorIndex'} = $wd->{wdGreen}; 
    } else {
      $font->{'ColorIndex'} = $wd->{wdRed}; 
    }
}
$document->Save;
$document->close;
[download]

If the constants don't load just use a color index of 6 for red, 11 for green

poj