Fei et al. designed a cement-based paint that cools both radiatively and through evaporation and that appears to keep buildings relatively cool even in humid environments. Although radiative cooling is effective at reducing temperature, it requires the material to be sky-facing. Designing a paint that also cools through evaporation allows the material to be effective when applied to the sides of the buildings as well.
I live in South Florida, which has a climate not too different from Singapore. We normally have to scrub down north facing walls and windowsills every years anyway, since the mildew growth is real. it doesn’t really cause any harm though.