Grease a piece of baking paper and place it on a tray or baking sheet.
Insert bamboo skewers into the apples and set them aside.
In a saucepan, combine sugar, water, corn syrup, and black food coloring.
Set over medium heat and stir until the sugar dissolves, then stop stirring.
Wash down the sides of the pan with a wet brush to prevent crystallization.
Cook the caramel until it reaches the hard crack stage (150°C/310°F), or test by dropping a bit into cold water to see if it forms hard, brittle threads.
Carefully dip the apples into the caramel, swirling to coat.
Place them on the prepared tray and let them cool and harden before serving.