Make the saffron syrup: Bring 1/4 cup water and the sugar to a boil in a small saucepan. Reduce the heat to medium low and simmer 3 minutes, stirring occasionally to dissolve the sugar. Add the saffron and remove from the heat. Let cool completely.
Put a scoop of ice cream in each of 4 glasses, then fill with the soda. Drizzle with the saffron syrup and top with candied orange peel.