Painting a spa, or?

Don't bother. A spa is more about kicking back, relaxing with a drink and your eyes closed than staring into the water through the bubbles and turbulent water and thinking about it's color.

One of my friends had it done. HE got a company that usually refinishes bathtubs to do it. They had never done a spa before. Think it cost him about a thousand dollars. This is pretty cheap really.

You can do it yourself, with a two part epoxy refinishing kit, but I would also drop a hundred bucks on something called an Ozonator -- it injects a stream of ozone into the circulating pump. The ozone disinfects the water, so you don't need to use the bromine. I'm not sure how the refinish would stand up to the hard chemicals. But with the refinish, and the ozonator, you should be fine. Is it acrylic or the poly?

Geez. Haul it to a boat yard or decent auto body shop. It's usually acrylic and can be painted with any number of products. Dupont Imron makes a beautiful spa finish.

Note that scratches show if the color is changed, and the paint is less durable than an acrylic finish, but maybe a few hundred bucks would get a top of the line finish.

Jeff