You will need to make 6 single batches of colored marshmallow fondant in indigo, blue, green, yellow, orange and red plus one double batch in violet. For each single batch, lightly grease a microwave safe mixing bowl with butter or shortening. Pour 2 ounces (a full cup) of mini marshmallows into the bowl. Sprinkle 1 1/2 teaspoons of water, 1/4 teaspoon corn syrup and 2-5 drops flavoring, if using, over marshmallows. Toss to coat. Double amounts for the violet fondant.