You can take advantage of PHP\'s associative arrays to guarantee uniqueness.

You should make the following changes:

// array_push($post_data, $values);
$post_data[ $cat_imploded ] = $values;
// return  $post_data;
return array_values($post_data);

So get_categories_map() code should look like this:

function get_categories_map( $data ) {
// get the posts type loja
$posts_list = get_posts( array(
\'post_type\' => \'loja\',
\'posts_per_page\' => 50,
\'post_status\'    => \'publish\'
));
$post_data = array();
foreach( $posts_list as $posts) {
$post_id = $posts->ID;
$post_title = $posts->post_title;
$post_estacao = wp_get_post_terms($post_id, \'estacao\', array(\\\"fields\\\" => \\\"names\\\"));
$post_cat = wp_get_post_terms($post_id, \'categoria_loja\', array(\\\"fields\\\" => \\\"names\\\"));
$cat_imploded = implode(\', \', $post_cat);
$values = array(
\'id\' =>  $cat_imploded,
\'title\' =>  $cat_imploded,
\'color\' =>  $cat_imploded,
);
if ($post_estacao[0] == $linha_select  && $cat_imploded != NULL ) {
// Build an associative array to ensure that only one instance of $cat_imploded exists in the array
$post_data[ $cat_imploded ] = $values;
}
}
// Use array_values() to convert the associative array into an indexed array
return array_values($post_data);
}

Another way to resolve repeated elements in array is to use array_unique :

$array= array(
array(
\'id\' =>  1,
\'title\' =>  \'title1\',
\'color\' =>  \'color1\',
),
array(
\'id\' =>  1,
\'title\' =>  \'title1\',
\'color\' =>  \'color1\',
),
array(
\'id\' =>  2,
\'title\' =>  \'title2\',
\'color\' =>  \'color2\',
)
);
$res=array_unique($array,SORT_REGULAR );
var_dump($res);
//output
array(2) {
[0]=>
array(3) {
[\\\"id\\\"]=>
int(1)
[\\\"title\\\"]=>
string(6) \\\"title1\\\"
[\\\"color\\\"]=>
string(6) \\\"color1\\\"
}
[2]=>
array(3) {
[\\\"id\\\"]=>
int(2)
[\\\"title\\\"]=>
string(6) \\\"title2\\\"
[\\\"color\\\"]=>
string(6) \\\"color2\\\"
}
}