The API can only react to things, not interrupt them. Also, there's no ping event (though I've asked for it several times!). The way I'd do this in a script is to designate pages that should be no-ping, then when a player is on that page (by splitting from the party or the ribbon being moved), store their current color and change it to transparent, when they move to a new page, set it back. All told, it would be a pretty simple script.