Let's see. An apple is red or green most of the time. An orange is orange. An apple has a smooth and thin outer skin, while oranges have thicker bumpy ones. An apple has a peculiar shape that I would describe as similar to a heart in 3-D with a truncated bottom point but some may be much more spherical, whereas an orange is more of an oblate spheroid all the time. Apples are in the family Rosaceae, while oranges are in Rutaceae. Both apples and oranges are fruits, and they both have families named after them in MLP:FiM.
It can be done!