if ($len === 6 || $len === 8) {
            $r = hexdec($str[0] . $str[1]);
            $g = hexdec($str[2] . $str[3]);
            $b = hexdec($str[4] . $str[5]);
            $a = $len === 8 ? hexdec($str[6] . $str[7]) : 255;