Make balls of tinted ice to cool the cocktails.
Mix 1 1/4 cups water with aperitif or liqueur (amount will depend on the desired color; see next step for measurements). Pour into the bottom piece of ball-shaped ice cube tray. Snap top on, and freeze until solid. Repeat to make additional balls.
To make the colors shown, mix 1 1/4 cups water with: 1. 2 teaspoons creme de cassis2. 1 tablespoon Aperol (a bitter orange liqueur)3. 1 tablespoon Galliano (an herbal liqueur)4. 1 tablespoon Creme Yvette (a violet liqueur)5. 3 teaspoons Aperol6. 2 teaspoons Creme Yvette7. 2 teaspoons Galliano8. 3 teaspoons creme de cassis