For the blue margs, I blended AL, blue curaçao & ice. Top with white candy stars. For the red, blend puréed strawberries, AL & ice. For the ice, blend AL & ice. To serve, mix everything ahead & store directly in your freezer. Come party time it will be ready to go.
You could also make a NA version with fruit ices or even easier, buy red, white & blue slurpees from your local convenience store.