add_filter('woocommerce_is_purchasable', 'gt_purchasable_products', 10, 2);
function gt_purchasable_products( $purchasable, $product ) {
	
	$purchasable = true;
	$is_a_member_blue = false;
	$is_a_member_red = false;
	$is_a_member_green = false;
	
	//Group name which makes all products non-purchasable
	$group_all_products = "Blue";
	
	//Each group name below should be in the same order with its corresponding product name. 
	//ie Red group is product10's group
	 
	//List of groups by name
	$product_groups = array( 'Red', 'Green');
	
	//List of products by name
	$product_names = array( 'product10', 'product 1');
	
	
	$product_ids = array();
	
	foreach ( $product_names as $product_name ) {
		if ( !is_null( $list_product = get_page_by_title( $product_name, OBJECT, 'product' ) ) ) {
			$product_ids[] = $list_product->ID;
		}
	}
	
	require_once( ABSPATH . 'wp-includes/pluggable.php' );
	
	if ( $group = Groups_Group::read_by_name( $group_all_products ) ) {
		$is_a_member_blue = Groups_User_Group::read( get_current_user_id() , $group->group_id );
	}
	
	foreach ( $product_groups as $group_name ) {
		if ( $group = Groups_Group::read_by_name( $group_name ) ) {
			$is_a_member[] = Groups_User_Group::read( get_current_user_id() , $group->group_id );
		}
	}
	
	if ( $is_a_member_blue ) {
		remove_action( 'woocommerce_after_shop_loop_item', 'woocommerce_template_loop_add_to_cart', 10 );
		remove_action( 'woocommerce_single_product_summary', 'woocommerce_template_single_add_to_cart', 30 );
		$purchasable = false;		
	}
	foreach ( $is_a_member as $is_true ) {
		if ( $is_true ) {
			if ( in_array( $product->id, $product_ids ) ) {				
				$purchasable = false;
			}
		}
	}
	
	return $purchasable;
}