Why sailing navies painted wooden hulls

Why did sailing ships shift from visible wood to painted hulls in the eighteenth century?

They had long used coatings, but better paint protected the wood and increasingly helped identify a navy's ships.

Wooden warships had long used coatings before their painted appearance became more familiar during the eighteenth century. Better paint increased both protection and consistency. The finish helped preserve timber against marine organisms and weathering. National schemes could also assist visual identification in battle, although rivals sometimes copied them. Hull paint served maintenance and recognition as well as decoration.