Sorry, guys, but the paint is there for nothing more than decoration. For years, people painted the trunks of Royal Palms in Florida with white paint in the hope that it would prevent insects from crawling up them. In fact, it does nothing to stop the bugs. The practice was extended to Coconut Palms during the first serious onslaught of Lethal Yellows back in the early 1960s. Again, the treatment was useless and the City of Miami lost almost half of their Coconuts.
The paint does prevent various lichens from taking hold and is often pressure-washed and repainted to keep the stately appearance intact. But as far as preventing any form of pest or disease, it's only a myth.
Ricky Ginsburg Boca Raton, Florida
(just a 75 minute plane flight from paradise)