I recall a lot of white tile roofs in florida ended up turning black from whatever.
Humidity, direct moisture, and degradation. Spanish tile works well but even if you reflect heat the radiation its still is swirling around causing convection (Does this conclusion even consider wind/humidity for instance) and eventually permeate/settle within the walls of your abode. A lot of white homes back in the day that installed central air when the tech became cost effective. Needless to say without central air, not a lot of people would live south of north Georgia.