(PHP 3>= 3.0.6, PHP 4 )
int imagecolordeallocate (int im, int index)
int imagecolordeallocate
The ImageColorDeAllocate() function de-allocates a color previously allocated with the ImageColorAllocate() function.
$white = ImageColorAllocate($im, 255, 255, 255); ImageColorDeAllocate($im, $white);