function randomColor() {
$str = '#';
for ($i = 0; $i < 6; $i++) {
    $randNum = rand(0, 15);
    switch ($randNum) {
        case 10: $randNum = 'A';
            break;
        case 11: $randNum = 'B';
            break;
        case 12: $randNum = 'C';
            break;
        case 13: $randNum = 'D';
            break;
        case 14: $randNum = 'E';
            break;
        case 15: $randNum = 'F';
            break;
    }
    $str .= $randNum;
}
return $str;}