To make the simple syrup bring the sugar and water up to a firm simmer and stir to dissolve the sugar. Add the lavender and remove from heat, cover and let steep for 1 hour. Strain lavender out and let cool.

Mix the lemon juice and water together and add the simple syrup. Colour with the food colouring if desired. Refrigerate and serve over ice if wanted. A splash of vodka makes a refreshing cocktail too!