Microwave white chocolate chips in a glass bowl at 60% power for 1 minute. Stir. Repeat, stirring until smooth. Place red candy melts in 2 small glass bowls and microwave as with white chocolate. Transfer to a pastry bag, snipping off a small opening at the tip.
Microwave semisweet chocolate in a glass bowl on HIGH for 1 minute. Stir. Repeat, stirring until smooth.
Spoon white or semisweet chocolate over 3/4 of each pretzel rod. Tap off excess and sprinkle with colored sugar or place on parchment or wax paper-lined sheet. Let dry. Drizzle with candy melts and decorate with sugars and nonpareils. (If candy melts harden, microwave for 20 seconds.)