Hawaiʻi has the highest residential electricity rates in the United States. A metal or dark-tile roof in direct sun absorbs that heat all day and re-radiates it down into the living space all evening — driving the air conditioner and the bill. Conventional attic insulation just slows the inevitable.
Ceramic heat-block coatings solve the problem at the source: they reflect and block solar energy at the roof surface, so it never enters in the first place.