Clouds and dust haze appear white because they consist of particles larger than the wavelengths of light, which scatter all wavelengths equally. But sometimes there might be other particles in the air that are much smaller. Some mountainous regions are famous for their blue haze. Aerosols of terpenes from the vegetation react with ozone in the atmosphere to form small particles about 200 nm across, and these particles scatter the blue light.
You have read this article Sky
with the title Blue light from the sky. You can bookmark this page URL https://lettersfromladygodiva.blogspot.com/2006/06/blue-light-from-sky.html?m=0. Thanks!