Reserve 1/2 cup frosting in small bowl. Stir food color into remaining frosting. Place cupcakes on serving plate, fitting snugly together and forming fishbowl shape. Frost top row of cupcakes with reserved white frosting. Frost remaining cupcakes with blue frosting. Place gummy candies on frosting. Sprinkle candies at bottom of "fishbowl" for "gravel." Cut and shape fruit snacks to look like seaweed or water plants; place on cupcakes.