<?php
declare(strict_types=1);

$image = imagecreate(2, 2);
imagecolorallocate($image, 0, 0, 0);
$unused = imagecolorallocate($image, 255, 0, 0);
imagecolordeallocate($image, $unused);
$new = imagecolorallocate($image, 0, 255, 0);
var_dump($new === $unused);
