// var_export($array) =

array (
  'Men\'s' =>
  array (
    'products' =>
    array (

// if a value is not listed here, it cannot be in child arrays
      0 => '31',
      1 => '32',
      2 => '33',
      3 => '34',
      4 => '35',
      5 => '41',
      6 => '42',
      7 => '43',
      8 => '44',
      9 => '45',
    ),
    'colors' =>
    array (
      'Natural (organic tee)' =>
      array (
        'products' =>
        array (
          0 => '31',
          1 => '32',
          2 => '33',
          3 => '34',
          4 => '35',
        ),
        'sizes' =>
        array (
          'Small' =>
          array (
            'products' =>
            array (
              0 => '31',
            ),
          ),
          'Medium' =>
          array (
            'products' =>
            array (
              0 => '32',
            ),
          ),
          'Large' =>
          array (
            'products' =>
            array (
              0 => '33',
             ),
          ),
          'XL' =>
          array (
            'products' =>
            array (
              0 => '34',
            ),
          ),
          'XXL' =>
          array (
            'products' =>
            array (
              0 => '35',
             ),
          ),
        ),
      ),
      'Silver' =>
      array (
        'products' =>
        array (
          0 => '41',
          1 => '42',
          2 => '43',
          3 => '44',
          4 => '45',
        ),
        'sizes' =>
        array (
          'Small' =>
          array (
            'products' =>
            array (
               2 => '41',
            ),
          ),
          'Medium' =>
          array (
            'products' =>
            array (
              2 => '42',
            ),
          ),
          'Large' =>
          array (
            'products' =>
            array (
              2 => '43',
            ),
          ),
          'XL' =>
          array (
            'products' =>
            array (
              2 => '44',
            ),
          ),
          'XXL' =>
          array (
            'products' =>
            array (
              2 => '45',
            ),
          ),
        ),
      ),
    ),
  ),
  'Women\'s' =>
  array (
    'products' =>
    array (
      0 => '36',
      1 => '37',
      2 => '38',
      3 => '39',
      4 => '40',
      5 => '46',
      6 => '47',
      7 => '48',
      8 => '49',
      9 => '50',
    ),
    'colors' =>
    array (
      'Natural (organic tee)' =>
      array (
        'products' =>
        array (
          5 => '36',
          6 => '37',
          7 => '38',
          8 => '39',
          9 => '40',
        ),
        'sizes' =>
        array (
          'Small' =>
          array (
            'products' =>
            array (
              1 => '36',
            ),
          ),
          'Medium' =>
          array (
            'products' =>
            array (
              1 => '37',
            ),
          ),
          'Large' =>
          array (
            'products' =>
            array (
              1 => '38',
            ),
          ),
          'XL' =>
          array (
            'products' =>
            array (
              1 => '39',
            ),
          ),
          'XXL' =>
          array (
            'products' =>
            array (
              1 => '40',
            ),
          ),
        ),
      ),
      'Silver' =>
      array (
        'products' =>
        array (
          5 => '46',
          6 => '47',
          7 => '48',
          8 => '49',
          9 => '50',
        ),
        'sizes' =>
        array (
          'Small' =>
          array (
            'products' =>
            array (
              3 => '46',
            ),
          ),
          'Medium' =>
          array (
            'products' =>
            array (
              3 => '47',
            ),
          ),
          'Large' =>
          array (
            'products' =>
            array (
              3 => '48',
            ),
          ),
          'XL' =>
          array (
            'products' =>
            array (
              3 => '49',
            ),
          ),
          'XXL' =>
          array (
            'products' =>
            array (
              3 => '50',
            ),
          ),
        ),
      ),
    ),
  ),
)