BU KODDA KOMBİNASYON SONRASI GÜZEL İŞ GÖRDÜ

$arr = [
    "color" => [["name"=>"red"],['name'=>'yellow']],
    "size" => [["name"=>"18 inch"], ["name"=>"15 inch"]],
    "type" => [["name"=>"plastic"]],
    "brand" => [['name' => 'something']],
];

function runFor($arr ,&$array, $keys,$index,&$positions){
    foreach ($arr[$keys[$index]] as $key => $espec){
        $positions[$keys[$index]] = $key;
        if($index + 1 < count($keys)){
            runFor($arr,$array,$keys, $index+1,$positions);
        }else{
            $item = (object)[];
            foreach ($keys as $key){
                $item->$key = $arr[$key][$positions[$key]]['name'];
            }
            array_push($array,$item);
        }
        unset($positions[$keys[$index]]);
    }
}


$array = array();
$keys = array_keys($arr);
$positions = [];
runFor($arr,$array,$keys,0,$positions);
$combo = array();
foreach ($array as $item){
    array_push($combo,json_encode($item));
}
var_dump($combo);