Random CSS Hex Color by PHP

$rnd = Array('0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f');
$rnd_color = "#";
for ($i=0; $i<6; $i++) {
    $rnd_color .= $rnd[rand(0,15)];
}

Reference: Random Hex Color