Why is the sky light blue in the morning, afternoon

Because of the way light scatters in our atmosphere.

Particles in our atmosphere reflect many of the wavelengths of light that come from the sun. The large wavelengths (red,yellow,green) reflect back, while the smaller ones (blue, violet) pass through, thus making the sky blue.

The sky can be red as well, watch the sun set. The sun will be at a different angle and allow larger wavelengths through (red, yellow, orange) and make parts of the sky a reddish color.

This will help put things into perspective: http://www.sciencemadesimple.com/sky_blu…