i want to create a function which will add to specific products an attribute programmatically. i use the below code but it doesnt seem to work.
$attributedata = Array( 'pa_color'=>Array( 'name'=>'pa_color', 'value'=>'black', 'is_visible' => '1', 'is_taxonomy' => '1' ) ); update_post_meta( $productID,'_product_attributes',$attributedata );
if i set taxonomy to 0 the attribute is passed to the product but it doesnt appear in the front end unless i press update manually to each product. what can i do to add attributes to product? i want to mention that the products are simple products not variable.