I want to add list of color to a product attribute with following code:

function wcproduct_set_attributes($post_id, $_attributes) {
        $i = 0;
            foreach ($_attributes as $name => $value) {
                wp_set_object_terms($post_id, $value, $name);
                $product_attributes[$i] = array (
                    'name' => $name, // set attribute name
                    'value' => $value, // set attribute value
                    'is_visible' => 0,
                    'is_variation' => 1,
                    'is_taxonomy' => 1
                );
            }
            $i++;

        update_post_meta($post_id, '_product_attributes', $product_attributes);
    };

    wcproduct_set_attributes($_product_id_data, $my_product_attributes);

$product_attributes is an array of colors and $name is pa_color and $value is color name. this function works but it add last color to pa_color.