1. Place the water and gelatin in a medium saucepan; let dissolve for 5 minutes. Add sugar and corn syrup, bring to a boil, and cook over medium heat until the sugar is dissolved, about 2 minutes. Add the tea bags, remove pan from heat, and allow bags to steep for 10 to 15 minutes to infuse the flavor.

2. Fill a large bowl with ice and water. Remove tea bags; transfer mixture to a bowl set in the ice bath to cool. Add the lemon juice and food coloring, 1 drop at a time, until the desired shade is reached. The color will lighten slightly when frozen.

3. Freeze mixture in an ice-cream maker according to the manufacturer's directions until set but not hard. Transfer to a chilled loaf pan, wrap with plastic, and place in the freezer until firm, 4 hours or overnight. Serve garnished with Chinese hat tuiles.