Prepare the lolly sticks on a baking sheet lined with ziplock plastic bags.
Melt two-thirds of the chocolate in a bowl in a microwave. Once melted, stir in the remaining third of the chocolate.
Spoon the chocolate into lollipop discs at the top of each of the sticks. (The ziplock bags will help to make the surface of the lolly shine.) Refrigerate for 10 minutes to set.
Meantime make the royal icing: Combine the egg whites, confectioners' sugar and 2 teaspoons water in a stand mixer fitted with a paddle attachment. Beat on slow speed until the icing is stiff and very white. Divide the icing between three bowls and tint with the three food colorings. Cover the bowls with damp cloth to prevent crusting.
Fit one piping bag with a thin star tip, another piping bag with a fluted tip, and a third one with a small thin round tip. Fill the piping bags with the icings.
Frost the lollipops: On each chocolate disk, pipe an outline in yellow. Fill in with lines or stars in pink or purple. Finish by piping a central blob in contrasting pink or purple. Leave for 15 minutes to set.
Meanwhile make the garden: Fill a tub or bowl with florist's foam. Make a lawn out of fake grass or green sugar. Plant the flower lollipops on all sides, so it's a 360-degree centerpiece.