<?php
    /* Gero o Hexadecimal */
    function randomHex() {
        $chars = 'ABCDEF0123456789';
        $color = '#';
        for ( $i = 0; $i < 6; $i++ ) {
            $color .= $chars[rand(0, strlen($chars) - 1)];
        }
        return $color;
    }

    // Dados Necessários Para o Sorteio...
    $nump='32';        // Numero de Participantes

    // Chamo a Funcao
    $sorteio=random($nump,1);

    function random($nNumeros, $nQuant) {

        $aRand = array();

        for ($i=1; $i<=$nQuant; $i++) {

            $aRand[$i] = $rand = randomHex();

            while (count($aRand) < $nNumeros)
                if (!in_array($rand, $aRand))
                    $aRand[] = $rand;
                else
                    $rand = randomHex();
            }
        return $aRand;

    }


     echo "<pre>";
     print_r($sorteio);
     echo "</pre>";