I'm really glad you liked the game 🤗
The trick with the high coconut trees is rather simple - the treetops are just actors, which are aligned with the trunks of the background image.
This is also the original reason, why the higher coconuts are white. Because I had only one color to work with for the sprites and wanted to keep the palm leafs in the same color as the rest of the trees (I did not know about layering sprites yet).
To make sure this different color actually makes sense to the player, I made the white coconuts give you 3 instead of just 1 coconut. This way getting the harder-to-reach coconuts is more rewarding and makes collecting coconuts faster when you need more towards the end of the game. Plus the white coconuts give the player something to strive for from the very beginning.