Remove stems from apples. Insert a dowel into each apple at the stem end.
In a microwave-safe bowl, combine semisweet chocolate and 1 tsp of the oil. Microwave at 50% power for 1 minute; stir. Continue microwaving at 50% power in 30-second intervals until melted. Dip apples in chocolate until evenly coated. Allow excess chocolate to drip back into bowl. Place apples on a parchment-paperlined baking sheet to partially dry.
In a separate microwave-safe bowl, combine orange candy melts and 1 tsp of the oil. Melt according to package directions, then transfer to a piping bag or a small resealable bag with one small corner snipped off. Repeat with yellow candy melts and remaining 1 tsp oil. Drizzle both colors over apples. Return apples to parchment-paper-lined baking sheet to dry.