For reference, here is what the Florida Building Code says in Section 424.1.2.5.3:
424.1.2.5.3 Stairs.
Stairs shall have a minimum tread width of 10 inches (254 mm) for a minimum tread length of 24 inches (610 mm) and a maximum riser height of 10 inches (254 mm) . Treads and risers between the top and bottom treads shall be uniform in width and height. The front ¾ to 2 inches (19.1 to 51 mm) of the tread and the top 2 inches (51mm) of the riser shall be tile, dark in color, contrasting with the interior of the pool. Tile shall be slip resistant, except when ¾ inch by 2-inch (51 mm) bull-nose tile is used and the ¾ inch (19 mm) segment is placed on the tread and the 2-inch (51 mm) segment is on the riser. All markings shall be tile, except that pools constructed of fiberglass, thermoplastic or stainless steel may substitute other type markings when it can be shown that said markings are permanent and will not fade over time. This exception does not extend to concrete pools that are coated with fiberglass.