Is the Mylo-sitting badge going to be a really small version of the full-size “dog sitting” badge?
Rather than have multiple colours for each time you camp, what about having a version of the camping badge for each major event?
E.g. JAE has a tent with a japanese flag on it; camping at a track day has tent + chequered flag; Retro Rides has a tent on a hill., RR-France has a tent with a string of onions… Japfest 2 would have a tent with a big bin.
That way, people can collect a set.
Edit: Alternatively, it might be simpler to make the camping badges triangular, and put the event image inside.