Думаю вот это:

```php
...
foreach ($product as $output) { 
...
```

Оставь просто:

```php
<?php
$output = "";
$ids = $modx->resource->get('id');
if ($product = $modx->getObject('msProduct', $ids)) {
        $colors  = $product->get('color');
        $putkart = $product->get('put_kartinka');
        $nackart = $product->get('nacenka_kartinka');
        foreach ($colors as $vid => $cval) {
            $output .= $modx->getChunk('Test', array(
                'color' =>$colors[$vid], 
                'nacenka' => $nackart[$vid], 
                'putkart' => $putkart[$vid]));
        }
}
return $output;
```

Думаю вот это: ... foreach ($product as $output) {