This is a cap to insert and pin in your standard 2" trailer receiver.
Printed in TPU, it will be durable and flexible.
PLA does not do well in exterior applications so I would not recommend it.
PETG is an alternative but TPU will give you a much better outcome.

Included above is a basic cap and a pirate themed one.

On the pirate themed one, I have included the inset. If you want to customize your own, create .4 thick inset and make sure your slicer can overlay the parts exactly.... then print the inset color, change filaments and print the rest over the top. As long as you don't exceed one .4 nozzle layer, it will work perfectly.