Are you allowed to wear nail polish in a hot tub?

To my knowledge there are no legal restrictions against nail polish in public hot tubs. In a privately owned hot tub, it would be up to the feelings of the individual owner, however in a lifetime of hot tub use and ownership, I've never heard anyone refusing, or even having a problem with a nail polish wearer, assuming you mean dry nail polish as opposed to wet and freshly applied. On the other hand, it has been my experience that the bubbling hot water can actually be hard on a very recent manicure, even when its had a chance to set. If you want to keep the polish looking good, you may want to make sure to wait a day or so before entering.