I baked this spring bouquet of cupcakes for my Weekend Baker post on the Cooking Channel blog. I was limited in space and wanted to go into a
bit lot more detail on how to pipe the icing roses. Creating these flowers is not at all difficult, but it helps to have some simple tricks of the trade. With a little practice and the right tools you can easily recreate these flowers. The contrasting color that tips the petals is one of those easy tricks that takes them from ordinary roses to extraordinary. Here is how I did it:
You can find my recipe for the cupcakes on the Cooking Channel 
Piping Icing (This recipe is easy to pipe with and it has lots of body, so the flowers will have structure and not flop over. Once it sits for a minute it has a crisp exterior and a creamy center. It is delicious with a 1/2 teaspoon of extract added to it.)
(makes about 8 large roses. It can easily be doubled):
8 tablespoons unsalted butter, softened
2 tablespoons shortening (This gives a little insurance that it won’t melt in your hands as you are piping)
4 cups confectioners’ sugar
4 to 6 tablespoons cream (you can also use sour cream, which cuts the sweetness a bit)
1/4 to 1/2 teaspoon extract (use an extract that is clear, so it won’t interfere with the colors you are piping)
Food Coloring  (I prefer gel or paste for intense colors)
To make the icing: In a mixer combine the butter, shortening, confectioners’ sugar, and salt. Mix on medium-low speed for about 1 minute. You don’t want to mix too fast or you will incorporate air bubbles into the icing. Add the cream 1 tablespoon at a time until it is smooth, but still stiff.
You will want several little bowl so to mix the individual colored icing. You will also need:
large rose Ateco Decorating Tip 128 
extra large Flower Nail, Extra-Large Rose, 3″ Diameter  (Ateco #914)
Large Leaf Decorating Tip 65s/263 
Kitchen Shear 
Create the color icing you want for your rose. You can do them all the same color or have several different ones. Start your colors light and add more color until it is just as you like.
Place the rose tip in the pastry bag. Line the narrow end of the tip with the seam of the bag.
Along that seam you will drip a thin stream of the food coloring, trying not to get it on the rest of the bag. This line of color will come out as the contrasting color on the tips of the petals.
Fill the bag with the icing so that it is about 1/3 full. You don’t want to over fill the bag or it will be difficult to manage as you are piping.
Squeeze the icing out until the contrasting color is coming out clearly.
Hold the rose nail between your fingers and thumb, you should be able to easily twist the nail. Now pipe a nice wide blob of icing onto the nail. This blob will act as the base of your rose, so you want it to be large enough and wide enough to support the rose. The larger the rose (more petals) the larger the base.
Now we will pipe the bud of the rose. Start by holding your rose tip strait up and down, with the narrow end of the tip up. The wide end of the tip will be touching the icing blob.
Squeeze out a ribbon of frosting and turn the nail, holding it between your thumb and forefinger, counter clockwise;
swing the rose tip up, around the top of the mound and back down to the starting point. This creates the rose bud.
Now make the first row of petals. Hold the tip so the wide end is touching the mound about half way up, starting right where the bud finished off. Tilt the narrow end of the tip slightly away from the center.
Squeeze out the frosting, turning the nail counterclockwise and move the tip up (increase the pressure) and then down (decreasing the pressure) in an arch.
Form the first row of petals in this way, starting each one where the last petal finished.
I usually do 2 or 3 petals in this row.
Pipe a second row of 5 petals, under the row you just finished. Tilt the tip out even more with this row so the petals appear to be opening up. Overlap the petals to hide any openings between them.
You can stop at any point. You may want just a few petals for a young rose or you can continue on for a more mature flower.
Once you have piped as many petals as you like, you will need to lift the rose off the nail and onto the cake. I do this by using a pair of kitchen shears.
You will want to cut only part way through, so you can lift up the rose on the blades of the shears.
Carefully place it onto the cupcake and slide the shears out from under the rose. You will need to make sure it is well anchored so it will not move around.
Using the leaf tip and green icing pipe a few leaves around the base of the rose. This is a wonderful way to hide any imperfections in your flowers.