Simmer apples and water - covered - for 10-15 minutes, or until the apples are cooked through and soft.
Transfer apples and any remaining water to a high speed blender or food processor, along with the granulated sugar and salt.
Blend until smooth, then divide into small mixing bowls.
In one bowl, add the green apple flavoring, citric acid, and food coloring - if using. Stir to combine.
In the other bowl, add the brown sugar and caramel flavoring, stir well to combine.
Divide each of the two mixtures between two silicone dehydrator trays, aiming to get half of each on each tray, in random drops. (Ours are about 11 x 10", and we used 2, perfectly. )
Use an offset spatula to spread the mixtures and LIGHTLY swirl together to form an even thickness on each tray.
Dehydrate at 135 F for 6 hours.
At 6 hours, check your fruit leather. It should pull up from the silicone relatively easily, and be soft without being sticky. If it’s not dried yet, put it back in the food dehydrator until it is. Once you’re happy with the dryness, remove the pans from the food dehydrator and allow to cool to room temperature.
Use a pizza wheel or sharp knife to cut the caramel apple fruit leather into strips. We like to stick each one to a square of parchment and roll them up, before storing in an airtight container. (Usually a Ziplock Bag) See notes on how to condition your fruit leather.