Let a participant pick a color from a limited palette (few, max 16 colors?) his dot will be shown. While this still sufficiently ensures anonymity. Different crowds on a rally could agree on a color beforehand. Bonus: this would look nice on the map :)
Let a participant pick a color from a limited palette (few, max 16 colors?) his dot will be shown. While this still sufficiently ensures anonymity. Different crowds on a rally could agree on a color beforehand. Bonus: this would look nice on the map :)