(PHP 3 >= 3.0.6, PHP 4, PHP 5)
The imagecolordeallocate() function de-allocates a color previously allocated with imagecolorallocate() or imagecolorallocatealpha().
<?php$white = imagecolorallocate($im, 255, 255, 255);imagecolordeallocate($im, $white);?>
See also imagecolorallocate() and imagecolorallocatealpha().