The sky appears to be blue in color as a result of it having the shortest wavelength as compared to other colors.
What a sight it is, when the Sun is perched brightly in the middle of blue skies with white clouds accompanying it. We’ve all wondered and marveled at the beauty of blue skies, but have no idea for why the sky chooses its hue to be blue! Well, here’s a lowdown about the same:
Though sunlight appears to be white in color, it actually contains all the colors of the rainbow within it. One cannot mark these colors out when sun light is emitted from the sun. However, if one holds up a prism against light coming from the sun, he would notice the sunlight scattering into the colors of VIBGYOR (Violet, Indigo, Blue, Green, Yellow, orange and Red).
Light travels to different places in wavelengths. So naturally, the different colors of light also travel through their very own wavelengths. However, the wavelength of each color of light is unique, and differs from any other color of light. Consequently, when sunlight passes through earth’s atmosphere, it travels through many air particles and substances, where the wavelength becomes a crucial factor. The blue color of light uses the shortest wavelength to travel, so it reaches faster than the other colors of light. Blue even scatters more through the atmosphere as compared to other colors, because of it traveling in shorter and smaller waves. This is the reason why we see the sky being blue most of the time.
However, this is only the case when the sun is high in the sky. As the sky gets lower and closer to the horizon, we notice a change of color in the sky. At the horizon itself, we see that the sky is white again. This is because the scattered colors of the light have to be re-scattered again, because the light has to travel through even more air than when the sun was high in the sky.
Therefore, the above was an account on why the sky appears to be blue.