[Jcbones]

You need to send the colors "black", "white", "grey", etc, through the form, and then process the imagecolorallocate once the form post back to the page.

Code:

<h4>Choose Color</h4>
<select name="color">
<option value="black">Black</option>
<option value="white">White</option>
<option value="grey">Gray</option>
<option value="limegreen">Limegreen</option>
</select>

PHP Code:

switch($_POST['color']) {
 case 'white':
       $color  = imagecolorallocate($bg, 255, 255, 255);
       break;
 case 'grey':
       $color  = imagecolorallocate($bg, 128, 128, 128);
       break;
 case 'limegreen':
      $color  = imagecolorallocate($bg, 194, 247, 0);
      break;
 default:
      $color  = imagecolorallocate($bg, 0, 0, 0);
}
imagettftext($bg, $fontsize, 0, $x, $y, $color, $font, $text ); 

Of course, you can specify all of your colors, and then use a variable variable. I wouldn't trust the input from a post variable for that though.