An example of sunlight passing through clouds during sunset results in what is often called the cloud's silver lining. pastel shades of blue, pink, purple, and green can be observed at times of cloud cover. what is the cause of these patterns in the sky?

Water in the atmosphere and within the clouds themselves cause light waves to refract and reflect, creating an assortment of colors. The patterns occur when light is absorbed by water droplets within the clouds. The amount of absorption that occurs depends on the temperature of the air.  The patterns occur when light is reflected from water droplets within the clouds. The amount of reflection that occurs depends on the wavelength of the light, and shorter wavelengths are reflected at a greater angle than longer ones. 

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