Last week, residents of Jonggol, Indonesia, were awestruck by the appearance of vibrant 'rainbow clouds' in the sky. This rare phenomenon, which quickly went viral online, features swirling bands of colors including pink, green, blue, and yellow. The Indonesia Meteorology, Climatology, and Geophysics Agency (BMKG) confirmed the authenticity of the phenomenon, attributing it to a natural process known as cloud iridescence. Ida Pramuwardani, Acting Director of Public Meteorology at BMKG, explained that this occurs when sunlight interacts with tiny water droplets or ice crystals of similar size in thin clouds. The light is diffracted, bending and separating into various colors, creating the stunning prism-like effect. However, cloud iridescence is not frequently observed, as it requires specific atmospheric conditions to align, including thin clouds and uniform particle sizes. Lenticular clouds, known for their smooth shape and stable airflow, are particularly capable of producing vivid iridescent displays due to their high altitude and consistent atmospheric conditions.