Write a PHP function to compares two multidimensional arrays and returns the difference

<?php
function key_compare($a,$b)
{
    if($a===$b)        
    return 0;
    return($a>$b)?1:-1;
}
function multidimenssional_array_diff($arr1, $arr2)
{
return array_diff_uassoc($arr1['c'], $arr2['c'],"key_compare");
}
//multidimenssional arrays
$color1=array('a'=>'White','b'=>'Red','c'=>array('a'=>'Green','b'=>'Blue','c'=>'Yellow'));
$color2=array('a'=>'White','b'=>'Red','c'=>array('a'=>'White','b'=>'Red','c'=>'Yellow'));
print_r(multidimenssional_array_diff($color1, $color2));
?>