(PHP 3>= 3.0.6, PHP 4 )
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().