Melt candy melts in a plastic or microwave-safe bowl in the microwave or stove-top sauce pan.
Warm corn syrup and add food coloring. Remember that your final product will be lighter than the color of your corn syrup. You can also add color later if you want.
Fold mixture together with a spatula until mixture starts to seize and resembles soft serve ice cream.
It is important to not over-mix or your modeling chocolate will get oily.
Wrap in plastic and let set until chocolate is firm but still pliable. Usually a couple of hours depending on how hot it is in your room.
Unwrap chocolate and knead until smooth, smashing any hard lumps with your fingers.
Re-wrap chocolate and place back in plastic wrap to set up until hard.
Notes
Your chocolate will be hard every time you to to use it and you will need to re-heat it a few seconds (5-15 depending on your microwave) before each use.Do not over-heat or it will get too soft and you'll have to wait for it to harden up again before you can use it.