whats going on with the text color. Could it have something to do with the pallet of the image?

Without having access to the original images I'd guess: probably.

Perhaps the easiest way to avoid the problem would be to ensure that the image files get loaded as 'truecolor' (Ie. full 24-bit colour). You can do that by setting GD::Image->trurColor( 1 ); prior to loading the image. You'd then dump the colorAllocate() call and specify the text color directly using its rgb value. Simply 0 for black:

    ...
    ## Set the default to truecolor images.
    GD::Image->trueColor( 1 );
    
    # create a new image
    my $im = GD::Image->new( $filename );

    if ($size eq "l") {
        $im->string(gdMediumBoldFont,27,44,"Secure ". GT::Date::date_g
+et(), 0 );
    } elsif ($size eq "m") {
        $im->string(gdMediumBoldFont,29,26,"Secure ". GT::Date::date_g
+et(), 0 );
    } elsif ($size eq "s") {
        $im->string(gdTinyFont,15,26,"Safe " . GT::Date::date_get() , 
+0);
    }
    binmode STDOUT;
    print $im->png;
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For colors other than black, I use a simple utility sub to convert rgb triples to their integer representation:

sub rgb2n{ unpack 'N', pack 'CCCC', 0, @_ }

rgb2n( 255, 0, 0 ); ## Red
rgb2n( 0, 255, 0 ); ## Green
rgb2n( 0, 0, 255 ); ## Blue
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