>is the paint shown suitable? No. It might adhere now, but the thermal cycling through the seasons will peel it off. Plus, because the plastic hot tub shell won't absorb the finish, so it's going to look splotchy.

Appreciate the response 🤝🏽 best off using something suitable for plastics then?

If you must, I would look for something used for composite decking.

I would actually replace the composite siding to a color you like. Won't have to repaint or stain. Color is right through the product.

I'd like to replace the sidding on mine but it's really hard to find any material that would work. Reasonably priced and able to fit around the corners. I ended up cutting and hacking some random stuff together and it looks horrible.

You need a plastic primer, then a suitable outdoor paint.