<?php

$color  =   array("红", "黄", "蓝");
$size   =   array("大", "小");
$cap    =   array("1G", "2G", "3G", "5G");

$foo    =   array($color, $size, $cap);

function get_all($e)
{
    $elem_total = count($e);
    $max = 1;
    for ($i=0; $i<$elem_total; $i++) {
        $len = count($e[$i])+1;
        $elem_size[] = $len;
        $max *= $len;
    }   
    for ($i=1; $i<$max; $i++) {
        $m = $i; 
        $item = ""; 
        $ct = 0;
        for ($j=0; $j<$elem_total; $j++) {
            $n = $m%$elem_size[$j];
            $item .= $n>0?$e[$j][$n-1]:"";
            $ct += $n>0?1:0;
            $m = (int)($m/$elem_size[$j]);
        }   
        if ($ct>=2)
            $all[] = $item;
    }   
    return $all;
}

$ret = get_all($foo);
print_r($ret);

?>