Adding a striped edge to a rose takes no special equipment beyond a second color of icing and the cheapest brush you can buy. Needless to say, you can use any two colors you want to make roses for any occasion (patriotic, Christmas, high school colors, etc.). In this case, I used two shades of pink. I started by mixing up a small amount of the darker shade (I used Deep Pink by AmeriColor):
Start by making the bases. Dab the glue stick to the rose nail and stick a parchment square to it.
Hold the bag with the round #12 tip and pipe a shape similar to a Hershey's Kiss by holding the tip just above the surface, then piping firmly. When the base builds up to about the size of a nickel, start moving the tip up and away from the nail. Stop pressure and pull the tip away. If the shape isn't quite right, either coax it into place with a finger dipped in powdered sugar, or scrape the "Kiss" off and start over.
Official instructions on the Wilton site for The Wilton Rose will tell you exactly which angle to hold your bag at for each row of petals. I just wanted to show you a brief example of what happens when you pipe the first wraparound petal (that should completely hide whatever color the base is)…
The possibilities really are limitless! Halloween roses, anyone?