Text overlay color on image

[Anon]

I want to overlay some text onto a loaded image, but when I do, it comes out gray no matter what color I tell it to be.

Here's my code:

<?php
$image=imageCreateFromJpeg("bgregsmiling.jpg");

$white=imageColorAllocate($image,255,255,255);
$red=imageColorAllocate($image,255,0,0);
$green=imageColorAllocate($image,0,255,0);
$black=imageColorAllocate($image,0,0,0);
$blue=imageColorAllocate($image,0,0,255);

imageString($image,5,40,40,"Greg", $red);

imagejpeg($image);
imageDestroy($image);
?>

I appreciate any help!