Golden light rays penetrate through the clouds lighting up this coastal mountain range. Ever wondered why the best sunrises and sunsets are always when its partly cloudy? Light scattering. Scattering occurs when light rays hit particles in the air (commonly water vapour and dust particles). This changes the direction of the light, leading to different colours being produced. Clouds form when air becomes saturated, or filled, with water vapour. The darker the clouds the higher the saturation of water vapour causing less light reflection. As different clouds all have different saturation levels of water vapour, they all reflect light to different degrees producing the stunning array of colours we see during partly cloudy sunrises and sunsets.