In a small saucepan, combine the sugar and water. Heat over medium heat, stirring constantly, until the sugar dissolves.
Remove the simple syrup from the heat and let it cool.
In a large pitcher, combine the cooled simple syrup, lemon-lime soda, coconut extract, and blue food coloring.
Stir gently until combined.
Pour over ice in individual glasses and serve right away.
Notes
You can substitute Torani Coconut Syrup or sugar-free coconut syrup for the sugar, water, and coconut extract.Keep the soda cold and add it close to serving time for the best fizz.Measure the coconut extract carefully because a little goes a long way.