Wash apples thoroughly and rub dry. Remove the stalks and stick the wooden skewers deep into the base. Bring 150 ml water, 500 g sugar and 1 teaspoon vinegar to the boil in two pots.
Add red or green food colouring and cook for about 6 minutes until bubbly. (If you have a sugar thermometer, wait until 155 °C is reached.) Pull the pots off the stove. Dip 4 apples one after the other into each pot and turn them until they are completely covered with syrup.
Place on a tray sprinkled with sugar and allow to cool.