Why does the Rising and Setting Sun appear Red?

When the sun rises in the east, it appears like a red ball. As the day advances, its color appears white, but again at the time of sunset in the evening, it appears red. Do you know why is it so?

We know that our earth is surrounded by the blanket of air called the atmosphere. Sunlight passes through the atmosphere before it reaches us. We also know that sun light is composed of seven colours- VIBGYOR. In the morning and evening, when the sun is near the horizon the rays have to travel about fifty times longer path in the atmosphere to reach us than it does in the noon. The dust, smoke and water vapour present in the atmosphere scatter away these colours differently. Violet, indigo and blue are scattered most and red and orange scattered least. That is why most of these two colours reach our eyes. As a result, the rising and setting sun appears red.