Fatal error: Uncaught ValueError: imagecolorallocate(): Argument #3 ($green) must be between 0 and 255 (inclusive) in /home/public/materijal/captcha.php:17 Stack trace: #0 /home/public/materijal/captcha.php(17): imagecolorallocate(Object(GdImage), 0, -2, 0) #1 {main} thrown in /home/public/materijal/captcha.php on line 17